At the start of Back to the Future, Marty uses Doc's video camera to record Doc saying among other things, that the experiment is at the "Twin Pines Mall"
Shortly after this Marty throws the camera in the Delorean, takes off and accidentally runs over one of those twin pines in 1955.
1955 Doc watches the tape, but conveniently talks very loudly at the point where 1985 Doc says the location on tape. You can't really hear him say the location.
Marty eventually brings the Delorean and video camera back to 1985 to the new "Lone Pine Mall". What is on the video tape now?
If you watched the tape would Doc say Twin Pines, or Lone Pine?