Unfortunately, my list of humorous (and unintended) online game teammate kills is far longer than my humorous death list.. but still death is death.
One notable incident I think I jotted down elsewhere: When I was a beta core tester for Red Orchestra in its mod stage, a cinematic test session was scheduled: all testers - core or gameplay - were supposed to play in staged battles so one of the guys could make screenies and get footage for a trailer.
I was on a German fireteam for this session, armed with a K98, and standing behind a fellow rifleman and a sergeant with an MP40 (who was my 'real life' clan leader at the time). Our trailer director - who was dressed up as a German as well - had taken position in a bush near a Russian bunker, giving orders. At first he directed the German team to shoot a few volleys in the air so he could take close-ups, then he ordered the Russian team to throw a few grenades, and so on. Finally he ordered the Russians to leave the bunker in panic, and gave the order for a 'real' battle, i.e., we were supposed to do a shoot-out with each other.
It was a great scene, but far too short to make the trailer - my first shot hit our hidden director, 'killing' him instantly.
One second of on-air silence. Then:
Crowfield (<-- me) : "Oops. I shot the director."
Wolfsglen (<-- fellow rifleman): "That means no Oscar for him, then."
The little TKing affair had a follow-up. For the next photo shoot, our director told my clan leader that he would lie down in the grass in front of him to take a few pics from that perspective.
Clan leader: "If you don't mind me tripping over your legs."
Director: "Anything, as long as you don't pull a Crowfield on me."
The clan leader whipped out his MP40 and shot the director 'dead'. Point-blank. To defend his clan's honor...
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I brought inadvertent death to yet another clan member (different game, different clan) during a training round of Battlefield 1942. I was driving a Jeep along a lonely mountain path and suddenly saw my teammate jog along the road - there was no flag in sight. Because I am basically a nice person, I stopped to give her a ride. Her avatar entered, I pressed the 'forward' key, slipped, catapulted my keyboard to the ground and crashed the Jeep full-force into the mountainside. My teammate jumped off to save her life... and was buried under the car. RIP.
BF 1942 was good for spectacular death scenes, anyway... once I shot down a plane and was subsequently crushed by the enemy pilot who didn't get his chute to open: Yaaaaaaaaaa-splat. And I don't remember just how often I died while dropping off an overcrowded fighter's wings while over the Channel...
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Another game: Counterstrike. My teammate and I (CTs) were down to very few hitpoints, so we both decided to hide under the stairs. We both tried to cram our bodies into the niche at the same time, and got stuck in a... um... very compromising position. Just then the last remaining T appeared, saw us - and the player nearly fell off his chair laughing. °-° His terrorist didn't survive this, as we both opened fire on him...