The game did not start and did not show that it was possible to exit it. Our team did not have 6 slots for the player, it did not show that he was not connected, and so on.
My duo party was spectating a match when our matchmaking popped. I clicked "Resume" which put me into the match lobby. My party member chose "Leave spectating", which booted him out to main menu. The match loaded in 5v6 and he was unable to rejoin. We remade.
Was in queue for a standard match, at the same time was spectating a game (id 117,829) when match was found my friends we able to join the pre-match lobby but I was not. There was no indication of my client trying to join and the other players did not see the countdown starting. Only once I quitted out of deadlock did the lobby close and everyone returned to the main menu
