Honestly this would be lovely when engaging formations. Sometimes you hit a bomber just right and it causes the formation to blow up and you only get 1 kill despite being the reason for breaking the formation apart (bombs vs .50 cal feels a bit broken tbf).
Disclaimer: I do not deal with these types of bans and have no behind the scenes information on how teamkill bans are made, this information is based on personal opinions and a general understanding from publicly available information.
That is likely where you are wrong. All types of damage done to Friendlies is recorded in some way and added as “points” to the system that then at some unknown total amount of points hands out a punishment of appropriate size. As far as i understand it those points are also compared to the amount of time passed and respawns done between getting those points to see if a punishment is necessary or not (Source: https://support.gaijin.net/hc/en-us/articles/200069301-Teamkilling). So i’m guessing that a gun-kill will land you more points than slight damage done by a bomb for example.
Reporting teamkills that the system might not catch still helps though. When teamkilling done in a way where it doesn’t show up in the kill feed and where the system might not catch it (like pushing a tank into water or pushing a friendly plane into the ground for example) it needs to be reported using the server replay report function and not the in-game complaint system. A guide on how to create a correct report for each in-game issue can be found here: (How to properly report players and contact Game Masters!).
And reporting does help, they did a ban wave for griefing/teamkills in November that explicitly included bans due to ramming.
Since then they have posted about teamkill bans alongside the cheating bans in i think all of the ban waves (not 100% if it’s all of them but i think so). So reporting does indeed work.