Even if I see the reasons about killing assholes I see a lot of danger in allowing team killing them in GLOPS without any consequence. In the RL situation you talk about, but in the first WW i believe that this was true for almost all the armies, maybe without having a dedicated detachment for it, but you had to strictly follow some orders attacking the enemy trench with a high chance of being killed, the only thing that could make the people move their asses was a stomach filled with alcohol and a gun pointed at the back, i think that you get the idea of the situation. It was a quite binary situation where you was attacking or you was a coward and a traitor so the soldier that was pointing the gun at your back could be at the same time your judge and your executioner.
In GLOPS the situation is completely different as every player is free to use the tactic he choose, to decide to risk more or less, and granting that right would give to the assholes a weapon more. Right now there is people that comes at your back with an MBT denying you the chance to go back under cover after firing and while you are reloading or have been spotted, if they don't even push you deliberately out of the cover with their tank that weight 2 times yours having you killed by the enemy, that maybe don't even spot you, but spot him behind you as he has no camo. Right now there is people that fire at you because their concept of you being an asshole is quite personal and debatable, Maybe you are so in their view because in the previous match you was in the enemy team and killed them 3 times in a row, or because you drive a faster tank and you went to cap a bombing run "stealing" it to them, or because they just have fun in grieving people and for an automated ban system all those reasons are as good as yours, @Lenticulas, even if probably you team kill for very different ones.
An other issue where team killing can happen beyond the willing to do it is when an ammo rack explosion happens, as it has some splash damage and is perfectly possible that triggering it in an enemy you kill with the splash a friendly that is near by and enough low health to die.
I also agree that being kicked from the battle punish your own team, not yourself, further more if you can go in queue immediately with an other tank.
I think that the right solution for GLOPS is to have the team killer marked but not kicked out of the match, if a player gets marked a certain number of times in the day or in a certain time then starts an automatic ban, first time of some hours, then days or even weeks if it happens way too frequently.
This and filing reports that are manually checked by the game assistance people, in which you include the recording of the game and a description of the reason why the other player was an asshole (he rammed me out of my sniping position to occupy it himself having me killed by the enemy, he was deliberately shooting at me or other friendly, he was shooting at me to reset my counter to capture himself something and so on), followed by a ban that could last even more then the one from the automated system, as an human can better judge if something is intentional and/or serious, should go together with the automated system.
Only being certain to have serious consequences like being denied to play the game for the evening, for some days or even for some weeks, can make some people stop to act as assholes, surely not being kicked from the battle, as well to be team killed but a self entitled judge works even less, as the only result is to respawn and keep being asshole, if someone wants to be so, if it is the way he has fun playing.
I think also that the splash damage and the bombing damage should not be used by the automated system as are something that can be not intentional or even tactically worth it, at least one time i had granted the victory of my team in a situation where both teams could win and had very few points left with a bombing that team killed a team mate.