That's not how it works... you don't just ignore everything that happens on the pitch just because the referee blew an imaginery whistle. There are rules that the referee can use that allows him to punish players before the play is restarted which should have happened in this case. Otherwise players could foul with attempt to injure opponents when they are offside knowing they'd get away with it.Why would they check anything after the offside ? Once hes offside the rest of play is null