How do you figure they were under fire?
As I understand it, the "firefight" lasted a few minutes and the remainder of the brief time on the ground was spent collecting loot and bodies of varying sorts (possibly rendering first aid to the lady who was shot in the leg), and destroying helicopter then and getting loaded up and outta there.
An invigorating forty minutes of one's life, no doubt, but I do not see any reports of them being under fire near the end of the mission ... only early on in that brief fire fight.