Calls like that are incredibly difficult to make. I have no idea if there was a touch or not on that particular play, but the down official made the call and overriding something like that is tough. whenever players in a situation like that complain to me and claim they didn't touch the ball, I respond to them by saying, "I'm sorry, and you were trying so hard to touch it too". They often laugh at that.
I understand that that this particular call was at a very crucial time in the match, but there is truly no way to ever know if that ball was touched or not. The down official called the touch and unless you are one hundred percent positive that there was no touch you simply cannot override it.