I have to believe that the team nor the NFL has seen it until recently. The first video is inconclusive at best, even if it is sickening.
And I think you make a good point. He probably did relay to his teammates that he was defending himself. In his own sociopathic way, he probably believes that he was defending himself.
But in this video it looks to me like they had a prior argument, for which he couldn't wait till the elevator to resolve. As soon as he gets in there, he hits the button, makes a comment that he knew would pee pee her off and she comes after him.
So basically he knew her well enough to know the reaction he'd get, and no offense but her arms are short. You have to be really, really horrible at handling yourself not to be able to check that without slapping her head into the elevator wall.