The decision not to penalize Alonso is dubious, but I think it's the right one under the circumstances. Those circumstances being the incredible ineptitude and indecisiveness of the FIA stewards.
Was it really so hard to get on the radio to Ferrari and tell them to have Alonso return the position at either of the next few corners? Surely not. When the Toro Rosso started falling back, it became harder, and then impossible, to fix the situation on track.
It's clear to me that Alonso gained an advantage by leaving the track, and that is behaviour that I think should be penalized. But because the FIA stewards diddled about, Alonso was no longer realistically able to return the place, and thus had to either get a drive-through or no penalty at all. With the Toro Rosso falling out of contention in the following laps, the 'advantage' gained by Alonso became near meaningless. I therefore think that the decision not to penalize Alonso after the race, was the right one.
But again: leaving the track is bad, and so is bad stewarding. This whole affair could easily have been prevented by having prompt stewards.
