How does this horse stay up?

[CSC]

I remember this race vividly, I took the horse that finished 2nd ridden by Ezpinoza that day. I wasn't really surprised by the decision of the stewards, if they went by the letter of the rule Chantal should have been taken down, however given it happened in deep stretch they probably deemed it insigificant to change a result. The best horse won and given the moderate odds of the second place finisher I was comfortable with their decision. As for Chantal's riding can anyone be surprised she can't keep a horse straight.