Christopher Lloyd opens up on his single biggest regret filming the Back to the Future trilogy

Christopher Lloyd has revealed his single biggest regret while filming Back to the Future Part III, admitting that skipping out on one iconic stunt remains a perpetual what-if in his career: “I should have done it.”

In his new memoir In My Own Time, the beloved screen veteran looked back at his time playing the eccentric Emmett "Doc" Brown, reflecting on the challenges of shooting the 1990 sci-fi Western finale.

The third installment sent Marty McFly (Michael J. Fox) and Doc back to 1885, requiring Lloyd to do an extensive amount of horseback riding.

While the production relied heavily on professional stunt performers for high-stakes sequences—from the gun-slinging duels to Marty’s close-call hanging—there was one specific action beat Lloyd desperately wanted to tackle himself.

“There’s a sequence in Part III where Doc is riding on horseback and chasing after the speeding steam-engine train that he hopes will once again bring Marty and the DeLorean back to the present day,” Lloyd wrote in his book.

“The scene called for me to ride my horse right up next to the rear of the train, until I was close enough to grab a handle on the car. However, I was plainly told not to actually grab that handle—in no way should I try to do that, or pull myself off the horse and onto the train.”

Directors and stunt coordinators strictly ordered Lloyd to pull back once he reached the edge of the speeding locomotive, letting the stunt team execute the dangerous leap.

Although Lloyd respected the decision at the time to avoid putting the entire production at risk, the temptation in the heat of the moment proved overwhelming.

“When it came time to shoot the scene, I had no trouble riding up next to the train car,” Lloyd recalled. “I mean, it was right there. The train is hurtling along at some fantastic speed, and I’m so close I can feel it going whooooosh as it rattled alongside me. I was within reach. And I just felt, I can do this. It’s there. I almost put everything in jeopardy. But I didn’t, and that was a close call.”

Even despite the regret, the third movie still remains his favourite of the franchise (Universal)

Decades later, the Taxi alum admitted he still cannot watch the climactic scene without a sense of lingering regret.

“Who knows what would have happened next? But whenever I watch the movie and see that scene, I still feel that pang in my heart: I should have done it,” he wrote.

Despite the near-miss, Lloyd confirmed that the Western caper remains his absolute favourite chapter in the entire time-travel trilogy.

“People ask me all the time which of the Back to the Future films I like best, and I have to say it’s Part III,” he said.