It was not going for the ball, it was a clear frustration move where he just threw an elbow and made contact with the Sixer player.
Rondo's foul wasn't called as a flagrant though it could have been, and if it wasn't the last 5 seconds of the game, it would have been. As far as a suspension, his case isn't as clear. At least his foul was trying to stop a guy from scoring, and though he basically admitted he wasn't going for the ball, during the play it wasn't positive that was his intent. Based on his statements though, he should probably be suspended, based on the play alone, I don't think that warrants a suspension.
I don't think Mchale got suspended in 84 when he tried to take Rambis' head off, so this wasn't even close to being that bad. I hate the celtics, though I may hate Vinny Del Negro more.