Because when a ref is called they feel pressured. He saw all the angles ans told the ref he was wrong, who caved. The ref got it right on field.
Ultimately its VAR's job not to intervene in that situation, so calling the ref over at all was a colossal mistake.
100%
My opinion on that statement has always been that he's being a snake. He knows they cheated, but by saying that he thinks he can jump ship if they're found guilty and pretend its because he has integrity.