You may have been
However you condemned the actions minus the facts. You unequivocally determined what transpired, came to judgment and were later proven wrong. In hind sight it looks even worse for you. Your burden of proof was a doctored video tape and nothing else.
"I'm happy to be persuaded otherwise"
Whether it was happily or otherwise is irrelevant. Your rush to find fault (incorrectly) is the crux of the argument.