People who don't understand that teamkills can be accidental.
On PDH I played as american, everyone was already at the second flag when the germans were on their way to capturing the first (observation bunker), I spawned down by the cliffs, saw the flamethrower and thought "This might be my only chance to use it!" and I grabbed it, first time I saw it in game as well.
Climbed a rope togheter with a guy called something like "dunno", when we came up and faced the bunker I thought I'd try out the flamethrower and hopefully take some germans with me.
So I fired in to the observation bunker (not through the door, but through the opening where the observation is going on), I had no idea about the area-effect of the flamethrower so I died together with Dunno.
He got mad as hell.
Later on the same round, the whole team had spent like 10 minutes trying to assault the vierling. I fixed my garand rifle grenade and thought that with it I'd take down anyone who was in it's vicinity.
Poof, BOM...
4 teamkills, and can you guess who was among them? yeah... "dunno".
"WTF!! BAN HIM!! IT'S NOT HIS FIRST TEAMKILL!!!!!"
Calmly I did explain that it was an accident and what I was trying to do, he was still mad as hell.
And apparently, some stupid admin did ban me just because of what he said.
so now I'm banned from thors brigade server. I don't know who to be most angry at, the admins or "dunno".
Edit: and of course I deeply apologized both times.