There is a green flag being waved by a marshall (hard to see him) but at the sme time Vettel’s in car display was still showing yellow. According to what I’ve read the marshall’s flag takes precedence. So he won it fair and square.
I agree with the comments if it had been an illegal pass there should have been a penalty though.
The only problem I have with F1 rules are the subjective judgements that they come up with. Mind you they seem to be more consistent now that Mad Max has moved on.
It was really close, Alonso proved what a great driver he is. I would love to see him and Hamilton in the same machinery again.