Dark Trooper Bugged

I was battling in GAC with Nightsisters against a Grievous team with Dark Trooper and Dark Trooper would not die. Just maintained two stacks the entire time. I defeated all the other enemies but Dark Trooper took no more damage. Then, after timing out another glitch happened where it treated it like I forfeited when I didn't it and reset all the other enemy characters to full health! Includes screen shot. My ally code: 882-858-452