During the car chase scene, the airbags in the BMW repeatedly appear and disappear through the scene.
During the car chase the damage on the front of the doctor's car goes from a "v" shape to a few bumps on the top.
Most cars, including BMWs, will not start after airbags deploy.
Matt Damon mentions he saw Bobby Orr's last game, since he was living in Boston he could not have attended the game because Bobby Orr's last game was with the Chicago Blackhawks and not the Boston Bruins.
When leaving the mayor after exchanging gun fire Cobby picks up a napkin and presses it against his gunshot wound but there is clearly blood visible on the underside of the napkin as he picks it up off the table where he hasn't even touched it.
A sign leading to a Switchgear Room has a typo stating "Swicthgear Room" instead.
During the police chase, the police car that hits the BMW is shown as an early model in one shot, and then a later model in the next shot.
When Cobby revs the motorcycle engine, his hand isn't on the throttle.