Death Lives - S3-E6
Revealing mistake: When Peter first meets Lois's dad, when they are talking, when Carter raises his eyebrows, for a split second, you can see his "extra" set of eyebrows.
The Most Interesting Man in the World - S12-E17
Revealing mistake: When Peter is attempting to sneak into the Drunken Clam whilst keeping an eye on Stewie, Peter rips out his eye and throws it towards Stewie, though his glasses are in the way of his eye. (00:03:10)
Revealing mistake: As Stewie is walking toward Herbert's house, he just suddenly appears mid-screen.
Revealing mistake: Right after the "Ghost Whisperer" cutaway, while Peter, Chris, and Lois are sitting on the couch, Chris' eyes disappear for a single frame. (00:09:10)
Revealing mistake: When Peter leans down to get the basketball, a dot briefly appears on his shorts, then disappears almost immediately.
Revealing mistake: When Peter says "kicking, Lois?", after being kicked into the stereo, his nose very briefly turns white. (00:20:00)
Barely Legal - S5-E8
Revealing mistake: Every time Cleveland's tub slides out of the house, there's never any plumbing attached to it. It just sits on top of the floor so it slides out easily. In this episode its very easy to see. (00:02:50)
Revealing mistake: Einstein's eyes briefly pop out of his head during the Theory of Relativity scene.
Revealing mistake: Death's right foot disappears when he gets up after he says "You know, my ankle is starting to feel better." (00:21:15)
Revealing mistake: While Lois is unbuttoning her shirt, Death's feet and legs aren't visible on the couch, even though he is lying on it.
Boys Do Cry - S5-E15
Revealing mistake: When Peter brands the cow, no burn mark is left on the cow. (00:18:20)
Revealing mistake: When Stewie and Brian appear in the future and watch the Griffin family in the future, the pole of the staircase Brian is holding is differently animated to the rest of the staircase. (00:13:25)
Revealing mistake: When the candy tree eats the kid, the kid appears mid-screen.
Chitty Chitty Death Bang - S1-E3
Revealing mistake: After the manager of the arcade takes money from other customers and cancels Stewie's reservation, Peter and Chris start walking along a row of arcade machines. Here the background was just copy and pasted over again, as they walk by the same place twice, and start a third time before the scene changes. (00:07:35)
Boys Do Cry - S5-E15
Revealing mistake: When Lois places Stewie on the floor whilst at the Little Miss Texas pageant, one of the girls is seen looking at herself in a mirror, only she doesn't seem to have a reflection. (00:15:35)
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