https://www.pcgamer.com/teamkilling-in-rainbow-six-siege-will-now-inflict-an-instant-ban/

Teamkilling in Rainbow Six Siege’s Casual mode is about to carry much harsher punishments. The first patch since the release of Operation Grim Sky expands the punishments already dished out in Ranked play while also bringing the same consequences to Casual.

Up until now, teamkilling twice in a match triggered a kick to the main menu. If you’re playing Ranked, the same would kick would occur, but the player would also be given the 30-minute abandon penalty that any player gets for willfully leaving a Ranked match. Under this new system, teamkilling gives the offender a 30-minute ban that locks them out of all matchmaking, including Casual, Ranked, and Terrorist Hunt.