The Salah goal has nothing to do with VAR. With or without VAR the Salah goal would have stood last night as the lino determined that the defender has made a deliberate action to play the ball and that resets the offside phase.
The issue is the wording of the rule and I mentioned last night, officials can't guess at the intention of players actions. You either have to change the wording, which will result in legitimate goals being ruled out or you allow officials to start guessing at what defenders intentions were, in which case you'll start getting hugely inconsistent decisions.