I not surprised that's what he is initially being charged with but I'm sure it'll get reduced to manslaughter. The prosecutor isnt going to risk going to court with that since he'll get no time at all if they fail to convict him of that. But the prosecution will have a far better chance of getting him on manslaughter.
That's a safe bet. Big fine and an assload of community service. He'll be arrested and get bail the same day; only jail time will be 4 hours in a holding cell. Money and fame talk.