I had heard that near the end of his life, near his 70's, he lamented that everything he had done was wrong.
The implication being he had stumbled on something that outmoded his theory, or simply showed it to be a specialized subset of something bigger.
And no matter, Einstein has been flat out proved wrong on at least one occasion, by J. S. Bell et al.
I prefer to think that Einstein's understanding of relativity was based on an incorrect assumption of certain absolutes... I think that if he was alive today, he'd be leading the way on quantum mechanics.
He had an incredible intuition about the structure of matter and the universe, and he made huge leaps based on small amounts of inormation.
I think that is rather incredible, and he would certainly be a great scientist today if he was alive.
I wouldn't trust anything by that Art Bell guy, he was kind of a kook, always interviewing UFO people and all . . .
Maybe he just recognized that he didn't understand the universe, after all.