Other mistake: In the scene where the brothers are going to kill the "fag man", the fourth man has his shoulders perpendicular to the brothers in the center of the room but the bullet goes straight through his chest. The shot wasn't even at a close enough angle to go through his chest like that.
Other mistake: The brothers executed the "Fag Man" by crossing their guns and the bullets coming out of opposing eyes. You can see when they show the flashback of the execution that the guns are held at nowhere near enough of an angle for the bullets to cross and come out the eyes.
Add timeNick Bylsma
Other mistake: In the scene where Connor and Murphy are waiting to hear from Rocco, the phone rings with an "electronic" style ringer, yet when Murphy quickly picks up the phone you hear the sound effect of a mechanical bell being jarred. The same bell is heard when he hangs it back up.