I see part of the problem is the desire is not undermine the referee. The VAR crew can overturn the goal because neither the referee, or anyone else, could spot the handball in real time. So no shame of the ref'.
With the penalty shout, the VAR crew think to themselves "The ref's dropped a bollock here, it's an obvious pen". However to pipe it down Oliver's ear, makes him look foolish and risks his credibility, so they leave it.
The ref could simply say he never saw the penalty incident, then there no need to look foolish.
What has actually happened is City have been cheated
You only have to watch a game to see how we are treated differently when it comes to decisions
Sterling booked but dembele not booked
Bernardo penalised for a foul when he was fouled
We could go on and on