Continuity mistake: In the opening shot of Apu serving his customers, you can see Martin wearing a purple shirt. However, later when all the customers are grumbling about the price, you can see Martin walk away wearing a white shirt.
Continuity mistake: Apu grabs the ham and crosses out of the expiration date with a thick black marker. When he places the ham on the shelf the black marker cross out is gone and the writing on the pack looks perfectly printed as before.
Continuity mistake: When the robber shoots Apu, he is shot around his leg. In the next shot, the wound is in his chest.
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.