UNSC permanent blisterbacks firefight

Yesterday I was playing three team firefight and an isabelle player had three blisterbacks that lasted until the end of the game without a spartan (alice I think) and no ghost in the machine active when I was looking. Is there some sort of glitch that causes this? I tried this with Jeromes omega team and it didnt work. The third player was colony so could they have taken the colonies blisterbacks and ejected out of them?