on any other lap, it would have been a legal move. Unfortunately it had to happen on the last lap, which makes it a little bit ambiguous as to the legality of the move. How are the drivers and teams supposed to know the difference between the safety car coming in as specified in the regulations:
40.13 If the race ends whilst the safety car is deployed it will enter the pit lane at the end of the last lap and the cars will take the chequered flag as normal without overtaking.
...and coming in because the mess on the track is cleaned up, and the race can proceed as normal...for 200 yards or so?
I wouldn't penalize Schumacher for this, as it is an ambiguity in the regulations, and a potentially confusing situation for the teams that is completely FIA's fault. In fact, as the teams were notified that the safety car would be coming in, there is a certainly case that the pass should be allowed to stand, as this is normal procedure for a safety car restart. IMO Schumacher should not be given the penalty, but maybe (?) the pass shouldn't be allowed to stand...unfortunately.
Whatever the outcome, FIA needs to clarify their rules to the teams and fans.