Brick fires 13 shots in rapid succession, without reloading from a shotgun that holds 8 shots.
9 minutes into the movie, Longoria (Celeste) was talking to Crawford (Brick). Frontal shots showed Longoria with her arms folded across her chest. Within seconds, rear shots showed her arms down at her side. These shots panned back and forth a couple of times.
In the credits, the scene where they get the check from Celeste, it's for $15k, she owes them $20k. She offered them $25k for the job. Maybe the truck will cover the difference.
10 minutes into the movie, Longoria (Celeste) pulls a bundle of money from her right back pocket of her shorts. Previous rear shots clearly show that the bundle of money was not protruding in her rear pocket.
Old man Mac has supposedly passed away, but he is still breathing.