There's a reason for the 0/5 team hit counter and everyone should use it way more (because it announces the TD to everyone, including any potential admins on the server).
Plenty of people report team damage to the ban section where they post screenshots of the TD without them having clicked M a single time ingame.
(The M function should though IMO have its wording changed to 'Do you wish to penalize X for Team Damage/Hit' instead of whether one think it was on purpose or not).
If someone team hits you should click M as much as possible, if you have a screenshot of someone hitting you 3 times within a very short time - and you could only click M on the first and second due to the speed - it is much easier to see that the TD was intended and not by accident. Every time someone requests a ban on a player I check out the accuseds account first, whether or not they had any prior bans, if not, they'll usually either get a short ban or a simple warning depending on the case.
Repeat offenders gets punished extremely hard, but that requires people to report these incidents to build up the database.
