Kevin,
Interesting that you see it that way. The way I see it, by my personal definition, Quiros is across the line at the top of the backswing. But he flattens the shaft early and aggressively during his transition. Tiger in 1997 and 2000 was across the line at the top but he flattened very early during his transition. I think that's the key: flattening very early during the transition. If you do that, then you can get away with a position at the top that's a bit crossed.
At least that's my opinion. Actually curious what Kevin and Lindsey think about position at the top vs. flattening in transition and implications for "The Tumble." I think what is done early in transition is a lot more important than exactly what position the golfer is in at the end of the backswing. Even if you're a bit across the line at the top, you can still get plenty of forward tumble if you flatten in transition.