Urm Jason? The mortar crews are several yards away from the treeline (That's where the initial attack by cart began, they retreated from that position quite a while ago.)
So the skeletal warrior would be jumping out of the tree... into the DEVGRU forces. They've already retreated two or three times, and they're nearly hugging the complex. I mean, if the suicide bomber went in with FBI, DEVGRU, and ARK corp support, yeah, it'd probably get through.
My most recent post even has all the security forces basically unloading all their rounds to create a large field of lead. How the skeletal warrior actually got past through well trained soldiers with almost no cover around to even hide leaves me puzzled.