Imagine that security guard returning fire into that room. May have saved many lives.
Lessee, they are on opposite sides of the door, Paddock has cameras and can see anyone approaching, the guard has a handgun, and Paddock zips off 200 rounds from (I guess) a modified AK, just for starters.
Odds of success (in disabling Paddock)? 1 in 100?
What will be interesting is whether the timeline says Paddock resumed shooting at the crowd. Just simply making him think police had arrived may have been enough for him to off himself. May.
In any case, Campos is one brave, and very lucky dude.