[JRutledge]

The rule only requires that the defender have feet on the floor before the player goes airborne. I can see what you are saying, but momentum has nothing to do with the actual rule. Now if you are suggesting the defender "leaned over" then that case is a different factor, but it appears he got his feet there first. I will say it was close, but I tend to give the benefit of the doubt to the defender when he is trying to make an effort to get in the way.

Peace