To be clear, aside from offsides they don't let play continue and let VAR decide. Andre Marriner will get two incorrect KMIs from last night as VAR correcting your decision doesn't count with the observation. VAR protocols say it can only get involved after the match referee has made a decision.
Do you mean after he stops play? A decision to play on is still very much a decision.
No, once the incident has happened and the referee has or hasn't stopped play VAR can get involved. The specific text relating to this is below ...
The referee must always make a decision, i.e. the referee is not permitted to give ‘no decision’ and then use the VAR to make the decision; a decision to allow play to continue after an alleged offence can be reviewed.