You are responsible for your account and the action that occurs on it. We have no way to determine who is playing on the account, but can only determine what the account says. You should work to ensure your account is secure at all times.
In regards to team ramming damage, usually this damage is minimal and thus will not cause significant impact to worry about.
Lastly, as you state they should be aware of what you're doing, you should also be aware of what your teammates are doing and staying situationally aware yourself.
Since this thread revolves around moderation issues, which is against the forum rules, I will be closing it up.
If you have issues concerning in game moderation and action, please submit a support ticket. Instructions for this can be found:
Fem,