I remember the scene - because I had been puzzled by the same question. Although Doc does explain that the time change hadn't caught up to them yet, it still seemed weird that Biff came back to "their" time as is. One would think he would have returned to a new time. But, if that happened, Doc and Marty wouldn't have gotten the time machine back so that they could go back in time. Of course, if Biff did come back to the alternate time, there would be no time machine (because the changes he made ensured Doc never got the chance to make it). So, that would have left an irreconcilable paradox. Then what would you do with the movie?

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"All that is gold does not glitter / Not all those who wander are lost..."

<font size=-1>[ This Message was edited by: nebularain on 2002-07-29 14:54 ]</font>