Just my opinion here, but I think this was all staged. As someone pointed out, Chris Rock stuck his face out. Will Smith slapped it, but Chris didn't seem phased by it. He didn't even move an inch from where he was standing. I have no doubt contact was made but very minimal. And then the exchange of words... I thought TV broadcasts implemented a delay in broadcast to catch unwanted and unscripted acts, but they showed it all. And then decide to retract or censor the incident after the fact.
Everyone benefitted from this incident. The Oscars, the actors, the producers, the sponsors, and there really was no harm committed. You know what they say. No publicity is bad publicity.