With the Dunk incident, wasn't it a case of VAR being consulted until they established that the ref had blown his whistle again (before the ball had crossed the line) and therefore VAR couldn't intervene to change the original decision (no goal, despite Mason subsequently giving the goal, before reverting to his original decision).
So it was a case of VAR determining that VAR had no jurisdiction and therefore couldn't be used to alter the ref's original course of action (so you're both right really)
All this does is show what a monumental farce the Lee Mason incident was
Problem with the VAR saying the second whistle cancelled the gaol out was when that whistle sounded. Most people reckon the ball had crossed the line before the whistle but is open to debate, what is certain the whistle made no difference to the ball going in, nobody stopped. As the timing was so debatable it stinks of a bodged cover up.