I don't think the referee has the right to do that. He has colleagues who can see the ball if he doesn't see it.
Also, Kevin saw the whistle in front of his face - but Sergio Aguero didn't see. Aguero asked for the ball in the right moment and Kevin delivered.
Any normal referee in the world would have allowed the play to continue.
What the hell, at least he could have saved the yellow card, if nothing else![]()
No, they wouldn't. Once the referee indicates to wait for the whistle, they're not going to go "yea let's play on, why not". You could also argue the Liverpool players were aware they had to wait for the whistle, he had plenty of time to take the free kick before the ref pointed at his whistle.