| When he comes back to 2015 after stealing the Delorean, he appears to be having a heart attack after he gets out of the car (getting his cane stuck in the door and leaving the top behind for Marty and Doc to find). In the DVD commentary, Bob Gale (the co-writer and producer) says the idea was that after Biff changed history to produce the alternate time line, Loraine eventually got fed up with him and shot him sometime between 1985 and 2015, which is why he appears to be dying when he gets back to 2015. reinforcing this theory, there is an extended version of the scene on the DVD bonus features that shows Biff fading away (like Marty in Part 1) after he exits the Delorean in 2015, but the end of the scene was edited out because they thought it would require further explanation that they didn't want to go into in the movie and ultimately wouldn't add much to the story. |