Why were audiences led to believe that Mike Webster died from a taser gun?

The 2015 film, Concussion tells the true story of Dr. Bennet Omalu uncovering the truth about brain damage in football players due to repeated head injuries.

The film focuses primarily on the Pittsburgh Steelers and former player and member of the Steelers, Mike Webster. The film depicts the physical and psychological problems that Mike Webster was suffering from before his death.

There is a scene in the film that shows Mike Webster sitting in the back of his pick up truck and using a taser gun on himself. The film does not explain the reasoning behind this. In actuality, he did this to himself so that he could knock himself out to sleep.

Desperate for a few moments of peace from the acute pain, repeatedly stunning himself, sometimes a dozen times, into unconsciousness with a black Taser gun. "The only way he could get to sleep."

Immediately following the scene depicting Webster using a taser gun on himself, we see him lying in the morgue awaiting an autopsy. This would lead audiences to believe that he died from a taser gun and that it was suicide.

Mike Webster was not a household name. Only die hard NFL fans and Pittsburgh Steeler fans knew who he was and how he actually died. Mike Webster died at a Pittsburgh hospital.

Is there a reason why filmmakers chose to imply that Mike Webster died from a self-inflicted taser gun injury?

After researching this film, it appears that most of the facts are correct. Of course, there will be certain facts that are over dramatized for entertainment purposes. The cause of death of Mike Webster seemed an important part of the story, so is there any evidence that filmmakers believed that Mike Webster died in this way?