Other mistake: When Homer is at Moe's, there is a boxing match happening on TV. There is a bald guy who is getting considerably battered by the opponent and gets knocked out, and then for some absurd reason he is victoriously standing as if he had won.
Other mistake: Apu already knew Homer because in the flashback episode, Homer's barbershop quartet, they were in a band. However, in the scene where Homer enters the Quick-E-Mart, Apu refers to Homer as steady customer as if he didn't know him.
Other mistake: After Ugolin (one of the French men looking after Bart) has taken Bart to the Chateau Maison, Cesar and Ugolin speak. (they aren't visible in this shot) Ugolin says "Escape is impossible", but the subtitles say that Cesar says it and vice versa for when Cesar actually speaks.