If he hasn't got all the way past, he hasn't passed him, he in the process of passing. As such the opposing car (in this case Webber) isn't trying to make a come back pass at all, he is still in the process of defending an overtake.
he's not defending, Hamilton had the line and was faster.
It was a silly attempt to try and get ahead, which paid of by luck not judgement.




- and I don't frequent Autosport's forums, might have a gander at that. I'm not saying it's LH's fault at all, but it was perhaps a tad easier for him to avoid MW than vice versa, in hindsight.