Continuity mistake: When the dentist wants to put Nemo in a bag, it's a resealable one with a seam at the top. When he finally catches him, it has changed to a normal plastic bag.
Continuity mistake: When a lighting rig bumps into a piece of wood, its front wheels and the wood are near the edge of a tile, but in the next shot, it is towards the center of it. (00:28:25)