I'm going to have to disagree with your statement. I don't think the guy was white knighting and I highly doubt he knew the person was transexual. He saw someone getting attacked and tried to get them out of the situation. That takes some balls. The mob got him afterward but he at least tried to do the right thing.

He was also driving what looked to be a work truck. I haven't seen many examples of people white knighting and driving a truck. Usually its a Prius or a Subaru.