They didn't look at it as a 'clear & obvious' error. An appeal system would change the whole dynamic. It would rule out the ridiculous 'C & O' error nonsense. They only intervene when they judge the ref has made a howler and it's the inconsistency of that that causes a lot of the issues.
A penalty appeal is made, the Ref disallows it. Then there is verbal communication and VAR, in my opinion, take their lead from that. Oliver..Doku.."Coming together....and VAR were influenced by that and there was no way they were going to overrule Oliver and send him to the monitor.
So another injustice. But if the captains have a say and why shouldn't they. So VVD appeals...Oliver goes and studies the video. Clearly a penalty.
But clearly the ridiculous charade will carry on.
And in this ideal scenario, if VVD is out of appeals by the 98th minute, what then? Will you accept the ref's call? No you won't, you'll still tell him he was wrong, and therefore the whole game is corrupt. Which it isn't.
VVD had his chance to appeal the incident at the time, but decided not to. One player made half an appeal but nobody else, not even those closest to the incident. Only after the game did the appeals come, which is too late at that stage.
Every time City have a penalty appeal, which is regularly, there is at least 3-4 of their players around the ref demanding he give it, even if it's debatable. So when the ref caves in, it won't be overturned. That's the difference.
You can only review a subjective incident on the monitor where the evidence from every possible angle, shows that the original decision on the pitch is clearly wrong, which is relatively rare. If every incident had to be reviewed, the game would last as long as NFL. Now I don't care how long it takes to get the right decision as justice is timeless, but most people would soon get fed up of 20 reviews of various incidents on a monitor per game, and so would you.