In the opening scene in the LA bank, Joe fires his shotgun into the ceiling. He ejects the spent shotgun shell; the sound heard on the sound track is a handgun or rifle cartridge case hitting the floor.
When Joe and Terry are robbing the bank with the big dollar bill as a curtain, Joe asks the manager to do the "all clear" which is to turn George Washington inside. On the next security camera shots, the dollar bill curtain is in its initial position.
When Joe And Terry are in Phil's Toyota they go to meet Harvey at his place, while their conversation is taking place the "Toyota" emblem on the front grill of the vehicle repeatedly disappears and reappears between shots.
When Dog does the falling stunt off of his house he is shown falling forward and lands on his back with his head facing the house. When they cut to the angle from the roof he is shown kicking his feet out in front of him and landing with his feet away from the house.
When Joe and Terry break out of prison, just before they smash through the
front gate, a black container with glass in front (housing a camera) and silver cables can be seen on the ground behind the gate from one angle.
When Terry and Joe arrive at a bankers house and announce to the banker that they are going to rob his bank, the banker faints (or spontaneously falls asleep due to narcolepsy). You can see the corner of the mat that he falls on.
The goof items below may give away important plot points.
At the end of the movie with the bank robbery when Joe and Terry shoot each other dead, the SWAT Team and the paramedics storm the building and Joe's cousin and girlfriend (posing as paramedics) go in and put Joe and Terry in body bags and take them away. When there's a shootout during a bank robbery and there are dead bodies, there has to be a doctor come in to officially declare them dead in order to prevent the possibility of the two men faking their deaths so that they can be declared dead and get away with the crime. Also, right after the police stormed the building there has to be a full investigation of the robbery before any dead bodies can be moved from the scene of the crime.