Christopher Lloyd regrets a botched stunt in Back to the Future Part III
Dr. Emmett Brown couldn't grab the train car handle as he wanted.
In the third installment, Dr. Emmett Brown, played by Christopher Lloyd, was supposed to grab a handle on a steam train car during a horseback chase, but he was explicitly forbidden from doing so. This impossibility still haunts him, according to his memoirs titled In My Own Time. He recounts that the scene, meant to allow Marty and the DeLorean to return to the present, would have felt more authentic had he been able to seize the handle. According to Écran Large, the regrettable detail remains one of the most memorable anecdotes of the trilogy.