Mentha, good points. And yeah, happens in the real world too. I know that of my own knowledge. But if you fall apart in a crisis situation, even when doing so would be justified, you may not make it out of that crisis situation.
I would actually expect that reaction of 'Can't deal with it now, have to keep going' to be commoner in the Minnaverse than here, where often there wouldn't be time to deal with, say, the loss of one's parent/child/village/significant other, because if you stop to wail and tear your hair, you and anyone depending on you are going to die as well.
Both immediate debriefing and the overt expression of grief may not happen in a crisis situation. Might be better for the participants if they could, but I don't really see how that could work here.