Banned for winning?

Games Halo 5: Guardians
1

I quit a game of breakout because the rest of my team left me to face a 4v1. I Immediately went into a slayer game and won. When I returned to the matchmaking screen I was notified that I have been banned for 9 HOURS. This isn’t the first time this happened but it is the longest ban I received.

WHAT THE -Yoink- 343?

2

If you have been banned previously then subsequent ban times do increase each time your account gets banned. The hammer, as far as I know, generally runs 1 game behind so that’s why action wouldn’t have been taken until after the match you won