Dennis Wideman claims a concussion caused him to deck a linesman -- but is that legit?

Jose Quiroz/Icon Sportswire

Dennis Wideman's hit on a linesman in January was haunting. The NHL had never seen one of its players steamroll a ref like that. Seven days after the incident, the league punished the Calgary Flames defenseman with a rare 20-game suspension.

But on March 10, arbitrator James Oldham downgraded that suspension to just 10 games after being swayed by Wideman's novel -- and medically questionable -- argument: Wideman claimed he was in a concussed state that kept him from knowing his actions would hurt the official. Call it the "concussion defense."

The arbitrator agreed. Oldham wrote, "I do not believe that in his concussed state, Wideman could or should have anticipated that his push would cause [the linesman] to fall and bang his head against the boards ..."

On June 8, the NHL filed a lawsuit to reverse the arbitrator's decision. According to the NHL, the decision cannot stand because the arbitrator exceeded his authority. It's currently awaiting the NHLPA's response on Wideman's behalf, which is due by Friday.

But the arbitrator's decision raises an important question that goes beyond the NHL's argument: Is the concussion defense legitimate?

For those unfamiliar with Wideman's case, the hit was pretty brutal. During the second period of Calgary's Jan. 27 game against the Nashville Predators, Wideman took a nasty -- yet legal -- check into the boards, which left him holding his head as he headed for his bench.

On his way, the six-foot, 202-pound Flames defenseman came upon linesman Dennis Henderson, who was skating backward along the boards in Wideman's direction. Suddenly, Wideman raised his stick, cross-checking the official in the back and violently sending him face-first to the ice, knocking him unconscious.

Henderson suffered a concussion. As of the date the NHL filed its lawsuit, he still hadn't been cleared to return to work.

Wideman later denied any recollection or intention. He said things were hazy after he was checked and blamed his actions on a concussion.

Wideman isn't the first athlete to blame violence on head trauma. The defense is popping up in criminal courts across the country, albeit in cases where defendants are claiming long-term brain trauma and are accused of committing grave crimes.

In January 2012, for example, Jordan Clemons, a 26-year-old former high school football star argued to a Pennsylvania jury that a decade of hard hits caused him to lose control and slit his ex-girlfriend's throat. Clemons blamed his violence in part on the numerous head collisions he'd suffered both on and off the field.

The jury wasn't moved, however. He was sentenced to death.

Blaming head trauma didn't fare well for Nathaniel Fujita either. A Massachusetts jury convicted the 20-year-old former high school wideout in March 2013 for strangling his high school sweetheart. A doctor retained by Fujita's trial team couldn't convince the jury that repeated on-field brain injuries contributed to his violent behavior.

Massachusetts doesn't have the death penalty; Fujita got a life sentence.

Just this month, former Arkansas and NFL running back Cedric Cobbs used brain trauma as a defense in federal court. He faced a maximum of four years in prison for his involvement in an OxyContin drug ring, but Cobbs received three years probation after convincing the court that repetitive brain trauma played a roll in his criminality and that he'd fare better with continued treatment.

Cobbs' case didn't involve violence. And Clemons' and Fujita's cases are different from Wideman's in many ways, from the type of violence committed to the authority dolling out punishment. But most notably, unlike in those two cases, Wideman claimed his violence came on the heels of a single concussion rather than after years of repeated head trauma.

According to Dr. Wayne A. Gordon, chief of rehabilitation psychology and neuropsychology at the Mount Sinai Brain Injury Research Center in New York, the notion that a concussion could immediately spark a violent attack is simply wrong. "Violent behavior is not a common short-term consequence of a concussion," he said.

"I see individuals who are months post- or years post-injury, and, yes, some become agitated for no reason. They lash out at people. They become more angry," Dr. Gordon said over the phone from his Manhattan offices. "But those are long-term issues. They're not things that emerge immediately."

In fact, peer-reviewed medical research backs Dr. Gordon. The research indicates that agitation, poor emotional regulation, difficulty exercising physical control -- some of the factors that could produce violent behavior -- are long-term consequences of concussions. Nothing indicates that these consequences appear moments after a concussion.

The two neurologists the NHLPA hired for Wideman's case -- who had examined Wideman via FaceTime four days after the hit -- argued otherwise.

One of the doctors testified at Wideman's arbitration hearing that the concussed often suffer "impulse-control difficulties" in the immediate postconcussion phase. He believed Wideman couldn't have intended to harm the official because "somebody whose brain is not forming cohesive plans is unable to suppress inappropriate behaviors." The other neurologist echoed those sentiments, adding little.

If widely adopted, this theory posited by Wideman's neurologists -- that bad behavior is an immediate postconcussion symptom -- could create a slippery slope for athletes.

Wideman's defense hinged on the notion that there is a cause-and-effect relationship between concussions and craze -- that head trauma converts players from being rational beings with self-restraint into lethal animals without self-control. If that were the case, concussed players could have to prove that they are not ticking time bombs post-impact.

The concussed could have to persuade their teams that they wouldn't need to be quarantined, sway their spouses to believe it's safe for them to be alone with their children, or even convince health insurers that they wouldn't pose a danger to themselves or others such that higher premiums would be necessary.

The "concussion defense" also could be subject to abuse. A hockey or perhaps football player could use it as a convenient excuse should they lash out violently during a game. And such abuse could effectively undermine the rules of organized sports -- rules that are in place to keep players safe, encouraging participation.

Many potential dangers could come from allowing concussions to excuse violent behavior like in Wideman's case. The arbitrator's decision endorsing the "concussion defense" could be that catalyst. Yes, it is just one decision by one arbitrator (who the NHL has since dismissed for undisclosed reasons). But the decision could be persuasive in other sports arbitration hearings, which often rely on prior arbitration rulings as guidance.

If the decision stands, it might be just a matter of time before the defense that helped Wideman avoid a 20-game suspension begins to work to his detriment and that of other players.

Adrienne Lawrence is an attorney with a B.S. and M.A. in criminal justice, as well as a J.D. from The George Washington University Law School. She practiced law from 2008 to 2015 before joining ESPN in August 2015.