I was just banned for winning a match. Ok, I did quit the previous game, but that was the only time in about a week, and we were losing horribly while down a player. The next match was a great one, and my team won 50 to 49. I went 17 and 10 with no betrayals or suicides, but immediately after the match ended it skipped the end stats screen and showed that I was banned. HOW DOES THAT EVEN WORK? HOW?!?
Ban thread is at the top of the halo 5 section. Give it a read and post there if you feel the need. You were most likely banned for excessive quitting, it takes the game a few minutes to catch up
You probably did something prior to trigger it. Because I highly doubt that it will ban you for winning.
Sometimes the ban takes a minute to kick in, and won’t d/c you in the middle of a match.
The system generally runs 1 game behind when placing bans. As above please see the ban thread in the Halo 5 forums for further help 