How not to use a bubble in crucible, just pop it and stand there. What did he think I'd do? Added bonus that his mate joined him!
Still love mayhem clash!
Same thing happened to me last night. I was stood there with GG when all three of them run at me - pop pop pop.
I think I earned it by basically soloing the whole thing. The first round was a right PITA compared to the following two (I think the bombs, enemy pathing & being "last guardian standing" played a lot into that). 

I found the 2nd round was the hardest for me bloody taken Archon bombarding with the dark stuff and the Taken Vandals sniping.