The position of the ax handle that Mugsy is holding in his hand changes. First the handle is being held completely through his hands, then later is is not.
When Bugs sets Mugsy up with the axe, Rocky chops off half the arm of the sofa. When Bugs subsequently starts unscrewing the ceiling light, the sofa is completely repaired and stays repaired.
At the same time that the arm of the sofa is chopped off by Rocky, Mugsy's hat is revealed to have been chopped in two. And like the sofa, the hat reappears in one piece in later scenes.
When Bugs is unscrewing the ceiling light, he uses a screwdriver, but he is using it on the ends of the screws where no place exists for the screwdriver to engage the screw (that is, since the screws appear to be wood screws, Bugs is unscrewing them from the pointed end, not the head of the screw). This is impossible.