I was doing the last mission of Against the Cockroaches, Morvin's Revenge for the fourth time. I finally trounced them, and only 2 of them were left, both badly hurt, and me at almost full health. I'm just getting ready to kill the boss and..."your connection to the server has been lost." Arrrgh. Refresh and of course it records that I've failed. Please fix. That is all.
Yeah, I've had connection losses like that. It feels even worse getting dc'd from a ranked game and losing rating as a result. Regarding the mission you're on though, personally, I find it works best to rush the boss berserker style. As soon as he goes down, you'll immediately win, regardless of the number of minions left.