[Mathew]

BUt in the look look look picture posted above, if the shoulder s were not represented as straight, but instead as a curved or slight 'v' shape then both shoulders could be onplane. Now maybe it is not what actualy happens in the swing, but it is not a law of logic that both can't be onplane unless you assume a straight line across the shoulders.

Nope, extensor action causes the shoulder flexability to be stretched towards the plane line. Thus the right shoulder is not somehow being stretched backwards towards the inclined plane that it is required to leave at followthrough, its being stretched towards the base of the inclined plane. So the shoulder flexability isn't an arguement. I mean just picture it in your mind what that would look like - anyone with a slight imagination can see thats not whats happening and your arguement is propesterous.