This is giving me a
migraine, but in response to
Quizro's queries :
Remember that alteration to causality in the
BTTF system of
time travel is gradual (so the photos can be used as a "gauge" of how badly the future is screwed up, for example). This would go some way to explaining the overlap (and the mall name discrepancy) at the end of the first movie. Two other valid and case-closing explanations are : budget and schedule constrictions led the production team to leave the mall sign as it was, no one would notice, I mean this is just a kid's movie vehicle for a short-ass
Family Ties star, right? (
How little did they know.) The other explanation is that working out all the time travel logic would extend the shelf life of the movie, and get some extra video revenue from
bored stoners and geeks renting it repeatedly to settle arguments such as this one.