"They're having to rewrite, they're having to do whatever they're having to do to deal with the situation," he said. "It's catastrophic. It's the worst thing that could happen to a movie.
"But it's not as bad as what happened to Paul. So everything is in perspective. He was a terrific guy and life is full of curveballs," the 62-year-old actor added.
Russell -- who was at Sundance promoting his documentary, The Battered Bastards of Baseball -- will star in the seventh film as a "father figure" to Vin Diesel's character.
[BBC News, E! News]
Celebrity Families of 2014 [PHOTOS]