Yeah, I'd be fuming, the ref should have called in in the run of play. As for the offside, that's what VAR is there for and to be honest, yes Kerkez was a red, but Semedo should have been off in the first half.
Other than having to hang on at the end there. I think that has to be the most satisfying win over GON. Other than a complete one sided goal fest (which tbf it should have been).
You got a win, red card, goals disallowed by VAR...perfect