Revealing mistake: When Peter runs across the dock after getting out of the boat, a large chunk of his body is missing.
Revealing mistake: When Peter says "kicking, Lois?", after being kicked into the stereo, his nose very briefly turns white. (00:20:00)
Answer: Mort is Jewish, and Walt Disney was said to be antisemitic. So it would make sense in a Disney universe all the inhabitants would share his supposed beliefs.
MasterOfAll