For the most part, it was pretty authentic to what actually happened in the years leading up to the present. It showed the strengths AND weaknesses of the characters, such as Omalu. And it took the NFL to task, deservedly so. I know Dave Duerson’s family was not happy with the portrayel of Duerson, but I found it to be realistic, given his role with the league.
There were moments in the movie that will stick, such as the scene involving Duerson and Andre Waters and the final scene in the movie, which was absolutely haunting.
If there is a message I hope people come away with it is the arrogance of the league and its employees during that time. Does the arrogance remain? I think so.