To me, I find this scary.
What other idiots are lurking at horse shows to video a snipet of people schooling their horse to post to YouTube and label it "abuse"?
Like said before, it is not abusive, but perhaps not the best way free up shoulders, unstick the rib, and get his hindend under himself. (ahem....counter bending) But we all have to start somewhere.
If the horse was scared, eyes rolled back into his head, running backwards to evade...different story. But he wasn't.
I DON'T LEAD 'EM AND FEED 'EM, I RIDE 'EM AND SLIDE 'EM.