I brought this up earlier in the thread, but in the final with a 4th official whose80% of his job is to ensure the proper substitution of players why do I have to tell him.

It brings to mind the corner kick trick play a U11 team did in state cup for which the referee was completely unprepared and awarded an indirect kick to the opposing team. The coach was told that in the future he should tell the ref that he "uses trick plays because U11 just do not do this kind of things". If it is within the rules why does anyone have to say anything to the ref?

Of course in your case it is dirty trick, But that is what the ARs should be doing.