According to the Somax Performance Institute, Tiger Wood's swing is now measurably worse with Sean Foley than it was with Hank Haney. They compare some of his swing problems to a guy crashing off a motorcycle as well as a Shakira hip shake.
The video shows footage of both old school and new school golfers, and discusses pros and cons of the swings. In addition, they discuss how his car crash could have led him to having the yips with his putting, and compare this to Tom Watson having the same problem in the 80s.
Some of it makes sense but he nearly won in December so it can't be as bad as it seems in the video.