Apologies for the late reply, but it states in Synthetic Programming and Guidelines that “If the threat is non-human or from a hostile faction, such as the CLF, Marine Law does not apply to them, so the synth can subdue or even kill them if necessary. However, synths are unable to perform active combat duties and will not perform combat specific orders, meaning they must not actively engage in combat unless in self preservation or in the defense of a USCMC Personnel.”
In this case, it would be in both self-preservation and defense of USMC personnel. If this is over-ruled by something else, please let me know. Thanks!
Edit: Apologies for the late reply. I was out visiting family for thanksgiving.