It is amazing they let Peter Falk do his own stunt running/falling down the hill to the car. You can see his face the whole time and there is no cut so it’s definitely him. Perhaps it got carried away and he actually fell and they just kept the scene because it was priceless?

The ColumboPhile covered this in one of his blog posts. It is, indeed one of the more memorable scenes in the show. I'm always amazed that Peter Falk didn't break his leg or his neck during this!

https://columbophile.com/2020/07/19/the-10-greatest-columbo-scenes-of-the-70s-final-part-of-the-top-100/

thanks for that link

You are welcome!