Had this happen last night in a siege battle. We had 2 really good players and the enemy had a balance of good players, we still defended our castle yet the teams were not fair enough to justify a multi. Oh and nobody got "autobalanced" either after the round. It was around 50 vs 50 as well.
IMHO it was because of "weight" of each player calculating in "long run". I.e. 1-2 excellent round played by some players does not really affect their "weight" for balance system.
BUT - in each round end calculating "current battles balance", what include not only total "weight" of all players but also dmg dealt by each player or how many kills did all players... (not clearly know it)...
And in this case because of excellent behavior of team members - result of the battle can be named as "unfair".
But it doesn't mean what team balance is wrong.
Just one team playing MORE teamplay, MORE accurate, MORE lucky (much more) e.t.c.
IMHO.
