Other mistake: When Evelyn becomes a rock, the other rock says they are in a universe where the conditions weren't right for life to form. During this scene, insects are visible flying and moving across the frame, and a grassy plant is visible in the lower right. These would not be present in a universe where life could not form. (01:41:06)
Other mistake: In the hot dog finger universe, everyone uses their feet for dexterous things, like playing the piano...but the pianos themselves are still designed exactly like our universe, at waist height where it's convenient for playing with hands, but very uncomfortable to play with your feet.