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).
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.
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.
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.