I know Brian doesn't mean bend the left wrist thru impact like that beginner.I have posted before on this matter and I have shown that the clubhead passing the hands just after impact like a lot of tour players do can be mistaken for bending the left wrist.The left wrist should not bend until well past impact however you should not also attempt to prevent the clubhead from passing the hands.This would prevent the "free wheeling" Kevin is talking about.
Trying to keep the hands in front of the clubhead is where a lot of TGM people overdo it.They are not only trying to maintain a flat left wrist.They are trying to prevent the clubhead from passing the hands and it looks goofy.Here is an example.
YouTube - Paul Smith & James Ramsey
It's a good thing gone bad!