its all fake but I think they maybe he fell the wrong way or something because he wouldn't call HHH "Paul" being his real name on live TV if you listen to the last ten seconds of Raw on Youtube.. you can hear the following.
Vince: Paul, Paul.. Paul am I ok ...
HHH: Don't worry, Vince you will be ok (holding his hand while he is on the stretcher.)
HBK: (behind them) make sure he doesn't move guys he could be paralyzed.
Is it just me or did something go wrong here, I mean it is fake and they meant for this to happen but maybe he fell the wrong way or something ? maybe he did hurt himself...
But I did think it was pretty funny once it first fell over John Cena came and tried to lift up the whole stage with his "superman" strength.... but he couldn't
(Edit, also about the above post maybe its a shot at TNA trying to make them seem like fools or something i dunno ? )