During the beginning of the movie we are introduced to a couple who have just come home from an evening out celebrating Halloween.
The blonde woman is dispatched by little Sam for disrespecting Halloween but oddly enough the couple appear during the Werewolf segment. Have I remembered the movie correctly? If so, surely that is a major goof!
It's not a goof. The stories are not told in chronological order, and they overlap. Even though the couple is arriving home at the beginning of the movie, this is an event which is happening much later in the night. When you see them at the parade, that's because the parade is taking place earlier in the evening. There's a number of these story overlaps, but you have watch closely for them.
I think the scene of the couple returning home was one of the last scenes chronologically. When Sam leaves Kreeg's house he looks across the street and sees them as they are returning.