The Posse Act did not apply to certain groups of soldiers there, we were under orders from the Governor NOT the federal government, therefore we can enforce civil law.
Read up on it, PCA only applies to ACTIVE DUTY troops and FEDERALIZED National Guard, if you are under orders of the Governor of your state then you can be used to suppress insurrections, enforce civil laws, and restore order. Disaster response is one such situation in which troops can be authorized to enforce the law in the absence of civil authorities.
BTDT
I think that the precedent has been set though, it looks a lot less menacing to have private security officers there than armed formations of troops patrolling the streets.
BTW the 505 PIR, 82ABN looked badass marching through the water with no kevlar, no vests, just rifles, LBE and wearing their berets.