Possible bug when both teams surrender

So, this is admittedly a very rare thing, and could really only come about through cooperative incompetence, but, seeing the enemy team surrender, the rest of the players in our team quickly started a surrender vote and completed it before the enemy's nexus could be destroyed. Shortly after, it did, but we were presented with 'defeated'. Now, what happened to us was totally our fault, but if this is unintended behavior, for the most recent team to surrender being given the loss, I figured I might as well point this out. I feel like the proper behavior should be for the first player to surrender to be the ones to actually lose, or better yet, for the surrender prompt to not be able to be created, and for existing prompts to be closed, if a team has already surrendered.