What I get from Joe Torre is the suspension was based on aggressively charging the ump while throwing the helmet in his direction (a foot or so away). There is no precedent.
The length of the suspension factored intent. Torre didn't think there was any intent on Lawries part with the helmet coming in contact with the umpire.
That's what I thought, which is why I'm surprised it was four games. I figured one, maybe two at most. Throwing the helmet into the ground deserves a game then maybe tack on another for the helmet making incidental contact with the ump.
Players and managers have argued and charged aggressively (no helmet obviously) in the past with no suspension.
