I believe there's a video of the "tank man" part of the protest. If I recall correctly, he stands in front of the tank, and then tank tries to shuffle around him unsuccessfully several times, after a while several other people approach and pull him out of the tanks way.

I don't really think it's debunking anything, but that person wasn't run over by the tank he stood in front of.

Edit: found it - https://www.youtube.com/watch?v=qq8zFLIftGk