If the round winner is determined in arena match (all other players are jailed, in my case there were one free player in both teams and right after arena match has started, they killed each other) and that match is tied, instead of counting a draw, game gives victory to the blue team. In my case red player even killed his opponent in arena, but within a second fell into lava and died. There was a message saying that the arena match is tied and both teams gathered in their jails. I guess in this case code just as usual checks if one of the team jailed and just as usual team with index 0 is checked first. If true, blue team isn't checked. I remember there was similar bug in Onslaught, when both cores blow up simultaneosly due to draining.