Not sure I understand your logic. When the safety car came out it picked up the leader, Button. Not sure how you've put Vettel in front. The most important point I was trying to make was, when the safety car is on track the rules forbid overtaking. The pit lane is considered a part of the race circuit, yet your allowed to overtake when you pit. I've just put forward a point that seems to me, wrong and have suggested a way to bring fairness back into safety car period, or more importantly, correct an anomaly. If your not allowed to pass when the safety car is on track surely that should include the whole track, and not exclude the pits.
Because when the safety car was deploed Vettel was in the lead because he hadn't pitted yet therefore the safety car would have picked him up. Webber was in front of Lewis too. Therefore by your idea they would have been able to come in and have a free pitstop and then make their way back into the positions they were in when the safety car came out. Thus putting Vettel in the lead.