This question is about the end of season three of Agents of S.H.I.E.L.D.
After they
trap Hive in a gel matrix and take him back to base
they just leave it in the hangar with the hangar doors wide open and a couple mall cops.
I understand the hangar doors were still damaged, but why leave it out there? That's idiotic and makes no sense. This was a terrible black spot on an otherwise good episode and season. Or, if it needed to be out there for some unexplained reason, why not put it under heavy guard? Even after the bomb went off, a couple of guards with guns could have solved things with bullets.
In all likelihood, everything would have been fine if they'd just taken some reasonable precautions. I guess that's what Coulson meant by "our mistakes"?