And that's precisely the problem.
It shouldn't have been left to Kavanagh to decide because his initial decision wasn't clearly and obviously wrong. There was so much going on in the area with that corner that it would have been difficult to say any of the possible decisions he could have made were clearly and obviously wrong.
Howard Webb, however, has by himself changed the goalposts by reducing massively the threshold at which a decision can be said to be a "clear and obvious" error. To give two examples, last Monday Everton scored at a corner at which an Everton player jumped directly into Donnaruma as the corner was in flight. That should have been a free kick, wasn't given, the review of the goal by VAR took about 5 seconds and nothing more was said about it. Then we have the Bournemouth goal, where a Bournemouth player grabbed hold of Donnarumma's arm and held on to him while the corner came in. Again there was a goal, again there was a review that lasted about 5 seconds, again nothing was said. Yet that was a much clearer, and much more obvious foul than the one on Saturday.
If a foul on the goalkeeper that was missed by the referee was a "clear and obvious" error on Saturday, it has been all season. But just find me one other example of a VAR reversal of the on-field decision that a goal should be given for a foul on a keeper at a corner. We all know they have been going on all season.
It was only on Saturday with the title on the line that the bar was suddenly lowered.