Continuity mistake: After getting the uranium, Stewie places it in the time pad and then puts the pad in his jacket pocket. After being confronted by Hitler who promises to spare them if they sing a musical number, Mort interrupts them, and it's seen that he is now standing on the time pad.
Revealing mistake: At Warsaw Temple, when Mort says "my bargain hunting Aunt Flo", production initials appear next to Brian's tail.
Continuity mistake: When Mort runs into Stewie's room, thinking it's the bathroom, there is a sign on the door that reads "Stewie's Room - Keep Out Brian." But a few moments later when Brian enters the room looking for Mort, the sign has disappeared.
Factual error: In the bit when Brian and Stewie are in Poland, the sign they are looking at should say Warszawa, not Warsaw.
Continuity mistake: When Mort goes into Stewie's room, there is a sign on the door that tells Brian to stay out of his room. A few minutes later when Brian and Stewie enter the room, there is no sign on the door.
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