Frank P,
Thanks for the link.
I suspect that Harmon has a different take on the separation and the notion that the swing mechanics he espouses result in injury to the crucial knee joints.
On the former, I have heard from sources I deem reliable that the breakup occured not because of differences in swing philosophy, but because Butch was too much in the limelight and leveraged the relationship to an extent greater than Tiger could tolerate.
In regards to the Haney's method, did Tiger's swing ever vary from a single plane? I know that he has always fought crouching as he goes back and the compesating move of raising on his forward swing, but he still seems to be doing some of that now.
I would think a flatter swing would put more pressure and tension on his knees as he is rotating (and torquing) his upper body more around his lower body, then releasing it faster to get back to the ball. Typically, a more upright swing has been linked with back problems (the reverse C follow through).
In any regard, if Haney's method is indeed easier on the knees, you would think that after five years of Hank's personal instruction, Tiger would not be popping his left knee as he clearly does at least with his driver. Maybe Tiger is just not a good student.