Agreed. The on-field indication from AT was definitely that the penalty was awarded for the second foul - we don't know if that means he played advantage or judged no foul in the first case. And I'm really unsure how far VAR credibility stretches in terms of recommending a different outcome there though.
If hypothetically the "second foul" was a legal tackle, I'm 99% sure they should carry out a VAR review in order to cancel that penalty decision, award the "first foul" penalty and then a red card is definitely viable because the OGSO was denied, it then just comes down to how O they think it is!
But because that "second foul" is in fact a foul, I'm not sure what the thought process would be. I tried typing it out but deleted it because I couldn't get it to make any sense to me!