No that would not be a mistake, that would be an ACCIDENT. I do not think that this is a difficult concept for one to pick up. A mistake is when you do something deliberately, than decide that it was the wrong thing to do. As in this situation.
No. Their actions went far beyond any "mistake". Their actions were wrong and reprehensible. I happen to be strongly pro-Israel. Israel has the right to exist and defend itself. But the actions of those particular Jews was abominable.