Cetus Eidolon hunt failed despite squad extracting after killing terralyst

[AndyTrout]

I used up all of my revives in the Eidolon hunt and so did one my squad mates while we were killing the Gauntulyst. Our other squad mates extracted after not being able to kill the Gauntulyst and the rest of the squad got the reward but I lost all the cores we collected and it said I failed the mission.