Honestly, I actually believe Artest when he said that he didn't mean to do it. I think he's so unaware of the potential consequences of his own actions that it's probably the truth. There's precedent for it - after the whole Malice incident, Artest asked SJax (completely seriously) if he thought they'd be suspended. Jackson's response was something along the lines of "Suspended? We'll be lucky if we're still in the league."
If there's one player in the NBA who doesn't deserve the benefit of the doubt for incidents like this, it's Artest. Intent or no, Stern needs to bring the hammer down on this one.