Zealot gave up on his team, but we still won...

We climbed personal assignment with @IndexGamingChannel, only to get this Zealot as a teammate on the last game before H40. We lost one game prior to this one with the same teammates, and Zealot player got upset with us but didn't leave the lobby. Instead, in this video you can see he plays extremely passively, rarely fights elites in melee, doesn't kill ranged or specials and only uses Chorus when he has to. Yes, he helped me revive Ogryn and Psyker when they went down on the mid event to Gunners, so he's done "enough" in this game for all its worth, but I don't get why some people play Havoc with random people if they get so easily upset. We weren't rude to him, we didn't blame him. It was his decision to try and grief his own team. Let's just hope it's not how he usually acts in his other games, and it was a one-off for him, a moment of weakness.