I don't believe that Webber was in any coast home mode during the battle. They were said to go into saving mode after the final stops and their battle started immediately when Webber came out of the pits. I believe that if Webber had lowered the settings, he cranked them right back up when he saw that Vettel is trying to get him. Vettel couldn't even pass him with DRS on the main straight so I have hard time believing his car would have had a serious power advantage.
He was in "coast mode" as stated by numerous websites, Christian Horner himself and Mark Webber.
Vettel got the pass even though being told to hold positions a couple of times. Lucky for Redbull and their reputation Webber did not retaliate by taking Vettel out which is probably what someone like Senna would have done.
Vettel has lost a major chunk of respect with the majority of fans, critics and experts. Especially after watching his performance on the podium when Martin Brundle interviewed him he was clearly delusional, smug beyond belief and didn't quite realise the shit storm about to hit him. I would have lol'd but I felt too disgusted to be honest.