If someone could test this theory I'd be very grateful: when someone in the game receives a message from a friend/clanmate through radio man approximately when the round ends in an Op.Con game, that game then immediately crashes.

I was OCing and right when it said "Round 2 Begin" we crashed. And this was just when my friend messaged me on radioman. So I'm not sure if that is what causes the OC game to crash, but you can look into it.