I honestly don't have a problem with way the Vipers were flown. They are attack platforms, that's what they do.
Exploiting the stalemate is a strong angle though and I agree with the idea that it's not a sporting approach to the game.
Where that line is crossed with these ships strikes me as impossible to call fairly, they have to play to their strengths to do well. Intent is not a provable thing, I certainly don't envy the judges.
Either way, credit to @Crimsonwarlock for taking them so far, I can't imagine the tactic amounted to easy flying and autowins.