Re how VAR works, VAR cannot get involved for simply disagreeing with the onfield call. They're only meant to intervene when the decision is clearly and obviously wrong and it's that phrase that results in some of the farcical decisions we see. A qualified official can spend 2 minutes looking at a decision with multiple replays and camera angles and still end up awarding the wrong decision, despite determining that it was the wrong decision, because in their opinion it wasn't quite wrong enough.
As Dale mentions in his article there were 26 incidents last season where the VAR didn't intervene when they should have and it's entirely down to this nonsensical 'clear and obvious' rule. It just confuses the situation and rather than allowing a qualified official to just make the right decision, they're instead having to decide whether the decision was clearly wrong enough, which is of course entirely subjective.