Factual error: During the Mike Webster autopsy, Dr Omalu asks Gracie for Mike's CT Scan of the brain again, but what she holds up is a MRI film, not CT. Then after interpreting the displayed MRI Dr. Omalu tells Gracie that this brain should be a mess, but it looks completely normal. Whereas the MRI shown by Gracie reveals several abnormalities like brain atrophy and degeneration due to complications of previous disease process. (00:27:45 - 00:28:30)
Deliberate mistake: While Donnie is training at Front Street Gym, when Rocky repeats, "One step at a time, one punch at a time, one round at a time," the closeup of two children watching from outside the ring is a flipped shot, note the backwards Nike swoosh logo and Everlast ring rope spacer. (00:53:05)
Revealing mistake: At the very beginning of the movie when Billy is getting his hands wrapped as Eli is taping his right glove, part of the H in his fighter tattoo has been rubbed off from when his arm was resting on the chair while they wrapped his hands. (00:02:40)
Continuity mistake: Before the last race while all the teams are ready to go, the sun in the background is below the trees but in the next shot the sun is shining on the runners.