But they DIDN'T sign their rights away to having their NIL used as movie characters otherwise, so they (or their estates) would probably have to be renumerated for that usage as soon as those characters do anything outside of the scope of the broadcasted episode, and outside of Carruthers NOBODY else who was present that day is going to be referenced by anything CLOSE to their real name or likeness.
Again, though, IANAL.
I wonder how much freedom they have with creative license. Like if they added a scene where Michael robbed a 7-11 at gunpoint, could the Larsen family sue for defamation?
I wondered the same thing about the biopic they did on Stu Unger. His daughter said most of the movie was made up, and a lot of his depiction is not very flattering. But to my knowledge, no legal action was ever taken.