Lewis Hamilton's crucial missed pit-stop in the closing stages of the Saudi Arabian Grand Prix came about due to a confusing situation on track, Mercedes boss Toto Wolff said.
Hamilton was seemingly presented a golden opportunity to stop on Lap 37 under a Virtual Safety Car, which results in a much smaller net loss than stopping under normal race conditions.
Doing so would have capped Hamilton's recovery drive from 15th on the grid with a decent points haul, but he finished 10th, scoring just a solitary championship point.
The VSC was prompted by a bizarre sequence of events as Fernando Alonso and Daniel Ricciardo both encountered car trouble in the final part of the lap and stopped their cars on the approach to the pit entry.
Alonso's car stopped right at the entry where the pit lane entry line starts on track, with Ricciardo's just a little further behind.
Hamilton had already slowed significantly in response to the yellow flags being waved in the final sector and in the belief that Alonso's car was still moving. Mercedes chief strategist James Vowles estimated Hamilton lost around six seconds in slowing in this way.
Hamilton, now driving cautiously at a reduced speed, then appeared confused about whether he could enter the pit-lane and he drove past.
Haas' Kevin Magnussen, running behind Hamilton, did enter the pits and would finish the race ahead of the Mercedes driver in 9th.
Radio messages from Hamilton to the Mercedes pit wall suggested the seven-time world champion was unsure whether he could pit without incurring a penalty, despite being told to "box", the F1 jargon for a pit-stop. Mercedes' pit crew had been ready for him to stop when Bonnington called him in.
Bonnington: So box, box. Keep an eye on the pit lane [light].
Hamilton: Car's slowed down?
Bonnington: Okay, box, box. Box, box.
Hamilton: Ahhh, too late...
Bonnington: VSC, so keep delta positive. The pit lane has closed.
Hamilton: Sorry about that guys. I just... there was a car in the way.
By the time Hamilton did pit two laps later the VSC had ended and Hamilton slid from sixth to 14th, but he could have exited as high as eighth had he pitted.
Hamilton has previous experience in similar circumstances, having lost what looked like an easy victory at the 2020 Italian Grand Prix when he pitted at a Safety Car deployment, only to find he had entered the pit-lane when the lights on entry had said it was closed for safety reasons. The penalty he received on that day meant he finished down the order and set up Pierre Gasly's memorable victory for AlphaTauri.
After Sunday's race Hamilton said he had been uncertain whether he could safely enter the pit lane without receiving a penalty for doing so.
"It was a difficult one," Hamilton said. "I saw Alonso slowing down, it was double yellow flags so I didn't push to overtake him, then Daniel was stuck in the pitlane so I didn't know if I could go in with a car sitting there. It was just not great."
Speaking after the race, Mercedes boss Toto Wolff said the confusion had ruined what had been an encouraging recovery driver from Hamilton, having started from 15th on the grid.
"I think on the encouraging side, staying on the hard [compound] was positive, wouldn't tell if it was fast, but it was positive," Wolff said. "And then obviously Alonso broke down during the lap, Ricciardo broke down with the engine, we told him to come in but there was a double yellow, a car slowing down and one stationary.
"It was just a confusing situation. He drove past and slowing down because of the confusion, and that made us come out behind Magnussen, and then obviously it's game over."