There is yet another factor in play here. Rahal himself did nothing wrong. The whole incident was the result of a brain lapse by the fuel man. (He never should have tried to reinsert the fuel hose).
Perhaps the IRL is looking into their options of levying a penalty that will hurt the team in general, more than it hurts Rahal personally, seeing as he did nothing wrong. That is fairer than punishing him personally by taking away any chance for a win by giving him a drive through, or whatever.
Yes, all the Honda and Rahal haters won't agree with that, but that in itself means nothing. The fact of the matter is he drove his heart out on that track for 500 miles. And in the process did nothing wrong. They didn't interfere with that. What they do after the fact won't effect what he did on the track yesterday. Which was drive a brilliant race.
All the open wheel sanctioning bodies, be they IRL, FIA (Formula 1), and even NASCAR operate this way. It happens all the time. They reserve the right to penalize the driver during the race, or the team in general, (which the driver is part of), AFTER. In Rahal's case they made the proper call. What they do remains to be seen. But whatever it is, it won't effect what he himself did yesterday, or should it.