Looks like a fairly straight forward(ish) scenario to me.
Helicopters (whatever the variant) fly into compound. One of them flares hard (like a UH60 is prone to do) and has a tail strike on the compound wall.
Tail structure structure falls one way (as in the picture), main wreckage falls other side of wall.
Remaining troops/survivors are now inside the compound. All hell breaks loose,
dems (white phos or similar) thrown into main wreckage.
All remaining troops onto cabs inside the compound(s). Therefore no time to scale the walls or go around and destroy tail boom.
Everyone gets the hell out of dodge.
As to what the cabs were?? Who knows??!!
All of course IMHO.