Team Killing is a known problem in team games played by Achievement Hunter, primarily Rainbow Six. Of the hunters to commit team killing, Gavin is the most notorious, closely followed by Ryan, while former Hunter Ray is the most common target (by Gavin in particular).
Killed Gavin, during Rainbow Six Vegas 2 Part 1, by strafing his aim too far right.
Killed Ray, during Rainbow Six Vegas Part 1, with a grenade.
Killed everyone after Gavin immediately team killed Ray. He explained this as having forgotten they did three maps the previous episode of Rainbow Six Vegas, including the one they were on.
Killed Gavin at the end of an argument between them.
Shot Gavin after someone said to watch behind him.
Couldn't move, then shot Jack from behind.
A bomber mishap saw Geoff kill Gavin.
Shot Trevor from behind in the head. (Trevor would later team kill Geoff in return). He claimed Trevor moved.
Mistakenly whacked Michael during the Prison Job and incorrectly thought it was Ryan.
Killed Gavin in a fight between them because they weren't friends (7 Days to Die)
Killed Gavin with his backswing (Chivalry, second team game)
Killed Ryan, who was covered in so much blood he looked like a red (later in the same Chivalry match)
Sniped Kerry in Trouble in Terrorist Town Part 2. Both were traitors.
Killed Geoff with a grenade mishap.
Shot Gavin, blaming it on the helicopter crashing. (Rainbow 6 Vegas Campaign Part 1)
Killed Ryan to prevent the reverse. (Ryan's Heist; Ryan had been attempting the same thing he did in Geoff's Heist but Ray was faster, having been clued in by Ryan repeating his line from when he killed Geoff in Geoff's Heist)
Burned Gavin to death mistakenly, though Gav was in a cluster of at least three red guys.
Accidentally killed Geoff (Chivalry)
Dropped a grenade during Rainbow Six Vegas Part 2, killing everyone.
Shot Ray in the back with a shotgun in Rainbow Six Vegas 2 ("WHAT ENEMY LOOKS LIKE M. BISON?!?!?!")
Shot Ray twice immediately into a map. One was justified as Geoff forgot they had completed that map previously.
Killed Ray with a breach charge. Ray and Michael both threatened to kill Gavin for it, but Gavin finished the map to live another day. (Rainbow 6 Vegas Part 3)
Michael walked in front of Gavin.
Threw a grenade that killed Geoff.
Shot Geoff in the back after a terrorist dropped in front of Geoff. (Geoff killed the terrorist before then)
Killed Ryan in a grenade launcher-induced explosion.
Killed Ryan via grenade after Jack's mishap.
Shot Michael in the face as he ran from an enemy.
Shot Geoff in a mishap.
Shot Ryan in a mishap during Splinter Cell Blacklist. A spy's EMP grenade may have been involved...
Notoriously kills his AI teammates in Halo, to the point GO! Episode 20 is based on it. (Gavin wins)
Bipped Jeremy in an attempt at testing Jeremy's guy's shield. (Rainbow 6 Siege Dustline DLC) Completely missed the shield he was trying to test.
Killed Geoff as he tried killing a terrorist and Geoff walked in front of him. (Same as above, later in same match)
Shot a fleeing Michael. (Different match, same video as previous two)
Shot Jeremy in a panic.
Tried shooting a terrorist and Jack walked in front of him.
Shot a downed Ryan as Michael got stuck trying to save Jeremy.
Immediately shot Michael as he said something.
Blew up himself and Ray during his heist, by driving into a gas pump.
Blew up Ryan with a grenade he threw just as the final remaining terrorist killed Gav with a TAR-21.
Shot Matt (Trouble in Terrorist Town part 5's final round). Was then killed by Ryan, who in turn was killed by Michael; Trevor shot Geoff. (Michael went on to kill traitor Jeremy)
Killed his fellow traitor twice in a game of Trouble in Terrorist Town with custom skins. Both times he got confused by a Glitch (who shows up as a Traitor on the screens of the actual traitors).
Jack was involved both times, once as the other traitor (the Glitch was Michael, but Lindsay won as the Jester), and the other as the Glitch (Gavin killed Lindsay).
Killed Geoff, removing him from a match. Gavin would subsequently fall down a hole, killing himself. (Rainbow 6 Vegas 2 Part 2)
Shot Gavin in a bomber mishap.
Didn't see Gavin or know he was there until too late.
Shot a downed Jack.
Killed Gus a second time.
Shot Gavin and Jack, and killed Jeremy with a grenade. (The grenade was meant for Gavin)
Killed Geoff, saying there doesn't have to be two of them left. (His attempt at doing it to Ray in his own heist isn't successful when a shotgun-wielding Puerto Rican turns faster.)
Whacked Geoff by accident while trying to open the armored truck his heist targeted. (Happens before the failed Geoff's Heist Team Kill Attempt #2)
Killed Gavin unaware that it was Gavin. (Chivalry) Later killed the same AI bot Michael accidentally killed.
Shot Gavin (Murder Part 1, resulted in Michael going over 9000 with "I TOLD YOU IT WAS JACK!!!!"). Was initially assumed to have been Geoff's doing.
Flattened both Jack and Ray on accident in the first two GTA Online videos; blamed both on not seeing the teammates' names until too late. Blamed Gavin for running him over earlier on in the same match as his mishap with Ray, but in actuality Gav only just nicked the vehicle that got him.
Killed Gavin with a grenade he threw before Gavin knew about it. (Rainbow 6 Vegas 2 Part 1; the second time Chaxle's AHHR R6V2 video goes slo-mo on Gavin dying via AH-thrown grenade, Gavin himself having thrown the first on the previous map)
Killed Gavin and Ryan with an accidental grenade.
Shot Gavin to get rid of the notorious team killer, though down Michael and Geoff by then via Gavin.
A breach charge mishap killed Gavin. (Rainbow 6 Siege; Would've been payback for Rainbow 6 Vegas Part 3 had it been Ray's breach charge)
Saw a bad guy, then mistakenly killed Michael. There's a chance he MAY have gotten the two mixed up.
Shot Ryan while trying to shoot a terrorist.
Accidentally killed Michael with his Lazer during his heist. (Michael walked into the exhaust; Ryan subsequently died leaving only Jack, who didn't do any robbing, alive)
Killed Ray. (Chivalry, first team match)
Killed Ray in getting a triple kill (same LP, other team game, counting it as one of his and Ryan's combined 39 kills (having initially mistaken Ryan as Gavin)).
Shot Gavin (And was almost killed by Michael for it) in Murder Part 3's fourth round as Jeremy was playing the long game.
Threw a grenade by accident, causing a triple team kill.
Shot Ray as he entered a door by accident. Immediately accepted the blame for it, saying it was on him (him being Michael, not Ray).
Shot Geoff, who couldn't move, then killed Ryan on Geoff's restart order.
Initiated Jeremy into Rainbow Six, then shot Ryan.
Killed Jack by accident in Geoff's Heist.
Killed Geoff and Kerry, who were supposed to die during Michael's Heist. (Lindsay tagged the wrong boat)
Shot Jeremy when he ran in front of Geoff (Murder Part 1)
Shot Trevor as he ran behind Jeremy (Murder Part 3)
Killed Ray and a bot (Chivalry)
Sniped Gavin (7 Days to Die Xbox) after Gavin baited him into doing it.
Killed Gavin from behind as another player shot Gavin from the front.
Shot Jeremy parkouring (Murder Part 4; he knew it was Jeremy because of Jeremy's skills with parkour movements in Gmod).
Rinsed the Detective and an Innocent as a Phantom. He may have confused the Phantom for the Killer (who he won as later in the same video).
Shot Ryan and Michael as Glaz, both accidental when they walked in front of him. (Rainbow 6 Siege, both in the same attempt)
Panicked on seeing a terrorist and shot Jack.
Shot Jack before Michael could.
Unfriended Gavin, then shot him. (7 Days to Die) Proceeded to kill Gavin a few more times over the subsequent parts.
a fight between Gav and Geoff caused him to make the realization behind this; friendly fire was off between friends.
Shot Gavin (immediately after Michael shot Trevor, Murder Part 3)
Shot Greg, claiming he was acting shifty, then shot Ryan a little later. (8-man Murder)
Shot Michael, saying Michael was in Jeremy's secret place (Murder Part 3)
Sniped Matt at the end of a fight (Trouble in Terrorist Town Part 5). Immediately realized he got the wrong guy, having hoped for Michael (the traitor).
Committed two team kills in Tase Fist (believed he had four when blowing up Michael with an explosive barrel (Jeremy: "OH I KILLED TWO TRAITORS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!" on learning Michael (a traitor) was who he blew up with the barrel) and shotgunning Trevor from behind (Jeremy was a traitor that round, successfully pulling the ruse Jack had tried earlier and failed)).
Blew up someone with a barrel (Jeremy: "Technically the explosive barrel killed him.")
Shot Fiona (who committed the LP's first team kill; Michael took the hit for her) after killing traitor Geoff.
Shot Michael in Tase Fist ("I hope i'm not getting tased." (learns Michael was innocent) "I'M GETTING TASED!")
Shot Geoff during a Rainbow Six Siege stream. (Trevor: "You can keep your dollar.") Geoff had killed him earlier in the same stream, hence Trevor telling Geoff he could keep the dollar the co-founder of AH owed the aerospace engineer.
Knocked his teammate ChilledChaos off the map during Sumo Remix. His color-blindness might've had a role in it.