On the boat, when Barney puts his wet suit top on, he is bare-chested, but when he gets into the pipe and removes the top, he's wearing a black t-shirt underneath.
When the guards enter the examination room where Casey is destroying the screen, you can see the edge of the set on the right hand side of the frame.
When Lusk puts the syringe in his pocket, the "State Mental Hospital" patch on his jacket is done with a marker and a pen. All of the characters that have that patch on their coats have the same crudely done patch.