My guess is that Player is off-plane because his right forearm is not perpendicular to his clubshaft - and I suspect that he has an arched left wrist rather than a flat left wrist.
Could it be that they are all on plane...just not the plane that you were thinking of?
How do we know the angle of their intended downswing plane line relative to the target ? (ie. open or closed or square downswing plane line relative to target)
Loading is the first time that it is crucial to be on plane...that is when you make your intended downswing plane line known (assuming your hands are sufficiently educated.