BUDAPEST, Hungary -- F1's top two teams, Mercedes and Red Bull, have been engaged in a war of words since their drivers, Lewis Hamilton and Max Verstappen, clashed on track at the British Grand Prix earlier this month.
Off track, tensions reached a boiling point on Thursday when Red Bull's push for Hamilton to receive a harsher penalty for the collision got heated before being rejected by the sport's governing body, the FIA.
Here's all you need to know about the ongoing spat and why its left both teams, and the FIA, with a sour taste in their mouths.
What's the background?
For the first time in seven years, Red Bull has a shot at the Formula One title and its top driver, Max Verstappen, is leading the championship. He's going up against seven-time champion Lewis Hamilton, who has had the fastest car for the past seven years but now faces an external threat to his domination of F1.
Ahead of the accident at Silverstone, Verstappen had been building momentum and arrived at Hamilton's home race following three consecutive victories. In order to stay in the title race, Hamilton had to fight back in Great Britain, and he did just that -- albeit with a very controversial outcome. After coming close to contact at races in Italy, Portugal and Spain earlier this year, Hamilton and Verstappen crashed into each other on the opening lap of the British Grand Prix while fighting for the lead. Hamilton attempted to pass Verstappen on the inside of the 180mph Copse corner, making contact with the Red Bull driver's right-rear tyre and sending the Dutchman into the barriers and out of the race.
Verstappen experienced 51 times the force of gravity on impact with the crash barrier and was taken to hospital for precautionary checks before being given a clean bill of health later that evening. The collision was investigated by the FIA's stewards -- essentially F1's referees -- and Hamilton was given a 10-second time penalty for being "predominantly" to blame for causing the accident.
Hamilton served his penalty during a pit stop in the race and, despite dropping to fourth place, fought back to take a home victory and secure 25 points in the championship -- closing the gap to Verstappen to eight points. The rhetoric after the race was highly charged, with Hamilton saying he had no reason to apologise, Verstappen saying Hamilton was "disrespectful" for celebrating while he was still in hospital and Red Bull's team principal, Christian Horner, calling Hamilton an "amateur" and "desperate".
In the week that followed the race, Red Bull exercised its right to petition a review of the stewards' decision -- a right that is available to all teams if they believe evidence that was not previously considered by the stewards had since come to light.
-Verstappen: Mercedes showed true selves at Silverstone
-Red Bull's Hamilton criticism was below the belt, says Wolff
What were Red Bull hoping to achieve?
In simple terms, Red Bull was trying to convince the stewards to reconsider their penalty and issue a harsher one. It was clear after the accident that Horner was furious at the outcome and Red Bull's senior advisor, Helmut Marko, even called for Hamilton to receive a one-race ban.
In Red Bull's eyes, a ten-second penalty -- the second most lenient penalty available to the stewards -- was not enough, especially as Hamilton went on to win the race for Mercedes while it was left with a driver in hospital and a $1.8 million repair bill.
But in order for the stewards to review their original decision, Red Bull needed to bring new evidence that wasn't considered at the time and was compelling enough to reopen the investigation. It emerged on Thursday evening that the team went to great lengths to try to do so, including using its reserve driver Alexander Albon and a two-year old car to stage a re-enactment of Hamilton's line through the corner during a filming day at Silverstone last Thursday.
The idea was to prove that Hamilton's entry speed and angle into the corner was always going to cause a collision, thereby strengthening its case that Hamilton was wholly to blame for the accident (rather than predominantly) and should receive a harsher penalty.
While it's normal and understandable for teams to investigate serious accidents to better understand their causes, it is unheard of for a team to complete a physical re-enactment of one side of an incident to try to convince stewards to change their mind. However, the Albon filming day at Silverstone, which the team had planned to run anyway, was only really intended as supporting evidence for simulations and in-race data it had compiled as its main argument for a harsher penalty.
"The test was pre planned from prior to the event because it was a promotional filming day with obviously a two-year-old car," Horner explained. "It's a way of keeping our reserve driver also sharp and race ready. That day had been planned for some time, it wasn't put on specifically for the re-enactment.
"What we did during the course of the test was ask Alex to drive a similar line to back-up the simulations that we conducted within our simulation tools, including the driver simulator, to demonstrate the outcome of driving that line and the necessity to where your braking point would need to be.
"We couldn't achieve the speed that Lewis did on that line. In terms of conditions, obviously it was pretty similar. And it was just a useful piece of data to reaffirm what we'd seen in all of our simulations."
The final dossier submitted by Red Bull included comparisons of GPS data between Hamilton's attempted pass on Verstappen on lap one and his successful overtake on Charles Leclerc at the same corner on lap 50 of the same race. The aim was to show how different Hamilton's approach had been on the two occasions -- again in an attempt to shift more blame onto Hamilton for the Verstappen clash.
Red Bull hoped the information it gathered -- plus simulations drawn from that data to show what was possible from Hamilton's position and speed entering the corner -- would be enough to convince the stewards to review their original decision. It claimed Hamilton hit the brakes 23 metres too late to stand any chance of making the corner without a collision, although Horner stopped short of claiming Hamilton collided with Verstappen on purpose.
"We presented that data to the stewards, they gave us a fair hearing yesterday where we talked through that data, the positioning of the cars, the speed of the cars, the fact that Lewis would have had to brake 23 metres earlier to have even made the corner, the fact that Max was on the same trajectory, identical to that of Charles Leclerc, that the result of Charles would have been identical had Lewis taken the same approach," Horner said.
"We presented that data, we feel that we had a fair hearing. The stewards felt that it wasn't new evidence under the confines of the regulations and so it wasn't opened into another hearing. We accept that."
Why did the stewards reject it?
In order to reopen their investigation, the same set of four stewards needed to be convinced Red Bull had produced new evidence that was "significant and relevant" to the incident, "discovered (as opposed to created)" and "unavailable at the time of the decision". Having read through Red Bull's dossier and summoned representatives from both Red Bull and Mercedes, they decided that the slides presented in the document did none of that.
In their summary, the stewards said, "what was presented to the stewards was not 'a significant and relevant new element" and that "the slides ... relied upon as new evidence were not 'discovered' but created for the purposes of submissions to support the petition for review."
In short, there was nothing in Red Bull's dossier that the stewards felt was relevant enough to reopen the investigation.
However, there was also an interesting final part of the stewards' summary, which stated there was "some concern" over accusations within Red Bull's dossier.
"The stewards note, with some concern, certain allegations made in the competitor's above letter. Such allegations may or may not have been relevant to the stewards if the petition for review had been granted.
"The stewards may have addressed these allegations directly in any decision that would have followed. The petition having been dismissed, the stewards make no comments on those allegations."
Although it was not stated in the summary, it seems the stewards were upset by questions from Red Bull during the review process over whether they had been influenced by Mercedes team boss Toto Wolff before coming to their decision at Silverstone. In the red-flag period after the accident on the opening lap of the British Grand Prix, Wolff sent FIA race director Michael Masi an email explaining why Hamilton's move had been legal according to the FIA's own stewarding notes.
Wolff followed up the email by radioing Masi from the pit wall intercom, asking if the email had been received. Masi told Wolff to take any evidence he had relating to the incident directly to the stewards -- who work separately from Masi -- during the red-flag stoppage, which Wolff then did.
In post-race penalty situations, drivers and team representatives are invited to supply evidence to the stewards, but it seems in this instance Red Bull felt as though Mercedes was doing the F1 equivalent of crowding the referee.
Speaking on Friday at this weekend's Hungarian Grand Prix after the request to review had been rejected, Horner said Red Bull was simply trying to gain an understanding of what was allowed in terms communication with the stewards and had not, in his opinion, suggested the stewards had been swayed by Wolff.
"Within the submission we talked about the process of approaching the stewards during the course of an event and I think the FIA have obviously subsequently clarified the process for that now which we're fine with and pleased for that clarification," Horner said. "So that was one of the main, pertinent reasons [for the request to review].
"At no point did we question the objectivity of the FIA. Of course through the right of appeal that other teams have also utilised -- I think both gentlemen to the left and right of me have used it previously -- we felt that we had new evidence that we wanted them to consider. We felt that they were objective about that.
"I think the one point that we did raise was that the objectivity could be prejudiced if you're influenced by having a competitor go in with data prior to a decision being made. And I think that that... we were assured had no influence on the decision-making and I think with the clarifications that have come out now regarding approaching the stewards' office during the course of a grand prix, I think that clearly deals with that and we're more than comfortable with that."
What were Mercedes upset about?
Once the stewards had rejected Red Bull's request for a review on Thursday evening, Mercedes issued the following statement expressing its own concerns about Red Bull's actions.
"In addition to bringing this incident to a close, we hope that this decision will mark the end of a concerted attempt by the senior management of Red Bull Racing to tarnish the good name and sporting integrity of Lewis Hamilton, including in the documents submitted for their unsuccessful right of review.
"We now look forward to going racing this weekend and to continuing our hard-fought competition for the 2021 FIA Formula One World Championship."
When asked by ESPN what exactly had been included in the documents that had tarnished Hamilton's name, Wolff said: "I think the remarks that were made during and after the Silverstone grand prix were just elaborated further in the document. Not always looking at the incident only but giving it a wider taste. That was, beyond other things, just a step too far."
He added: "I think everybody needs to decide if they want to apologise or not. We felt that comments that were made during and after the race in written statements and in the meeting itself were below the belt. It's not up to me, nor would Lewis want that, to demand any apologies." Although Wolff opted not to make a direct reference to the content of the documents submitted to the stewards by Red Bull, Mercedes clearly felt the post-race comments by Horner were doubled down on in the crash dossier. Yet Horner claimed his team had not intended to tarnish Hamilton's reputation and was simply acting in its own interests.
"Well first of all it was absolutely not a personal attack on Lewis Hamilton," he said. "Lewis Hamilton is a seven-time world champion and everything that he has achieved stands for itself.
"If it was any other competitor on the grid, we would have taken the same issue in the manner that we did. I think that I'm entitled to an opinion on that incident, as is everybody else.
"Obviously at the time, emotions are running high. We've got a driver needing to be taken to hospital for precautionary checks after an accident which would have definitely knocked out your average human being, we'd lost the car in its entirety under a budget cap environment for something the stewards didn't deem to be Max's fault.
"So there's nothing personal about it, but even a seven-time world champion can make mistakes, or misjudgements. That's just a fact of life. At no point has this been personal about Lewis and it would have been the same with any other driver and any other team on the grid."
What happens next?
The only thing the two sides appeared to agree on ahead of this weekend's Hungarian Grand Prix was that it is now time to deescalate tensions and move on. Barbs were still being thrown during press conferences on Thursday and Friday, but Red Bull has made clear that it has no intention to pursue the issue any further through the FIA's formal process.
"The simulations that we conducted, and of course with the size of the accident that it was we will always conduct a thorough investigation," Horner said. "I mean a 51G impact causing a driver to be hospitalized and the total destruction of a car is something that we will always take incredibly seriously and the driver's safety is our paramount concern.
"So of course we looked at great detail at GPS data, the speed of the cars, relative lines at different points of the grand prix, the overtake on the same corner with Charles later in the race, what would have happened if Lewis would have approached it in the same way and obviously taking all of that data into account we felt this was relevant and new evidence with the simulations as well that we'd made, and obviously looking to verify that through actual data.
"We felt there was obviously enough, it was our entitlement as a competitor and of course this is a sport where all the marginal gains count so absolutely it's our duty as a team competing for this world championship to absolutely leave no stone unturned. We felt it warranted a review -- a fair review -- it wasn't the response that we were hoping for but we accept it and now we close the chapter and move on.
"I think we are set up for a fascinating second half of the year," Horner added. "I think it's inevitable that these two drivers are going to be starting within close proximity at potentially the remaining 12 or 13 races, we've seen the outcome of this incident and now similar incidents, and I just hope that doesn't play a role in the outcome of the championship and in future races."
Wolff added: "I think Formula One needs content, and controversy, as long as it is around the sport, can be quite entertaining.
"But there are certain boundaries we need to respect and the sport should unite and not create more polarisation, and especially in a sport that cannot be proud at that stage yet about its diversity and equality, and we just need to get the words right, and therefore let's aim to de-escalate rather than to fuel."
The Hungarian Grand Prix is live on ESPN at 8.55AM (ET) on Sep. 1.