That requires aditional coding which isn't going to happen. M reporting is worthless. By the time you press 5 times M you are left with less than half HP and the idiot who wounded you will rejoin and keep doing what he did before kick.
That is why some native servers implemented reflective damage, when you teamhit someone damage you deal is taken from your HP pool. Sounds horrible and has great potential for trolling, but in reality works very well. Forces people to play differently, enforced much cleaner play style.