I will not mention which teammate ruined me, but he/she did. However, I was doing the Sheiled Brothers Strike for the Tex Mechanica Shotty. It took a LLOOONNNGGG time, and was so close to doing my bounty. I had to redo it because a former teammate had ruined it by killing one Valus with a heavy weapon, not a shotgun. THIS TEAMMATE DID THE SAME!!! He joined at the end, while I did a lot of work trying to kill them, and HE KILLED ONE WITHOUT A SHOTGUN. I think that because I used a shotgun, I should get the quest step completion. Now I get to do the strike a third time because of this person who must not have read the bounty!