Quite aside from the firing, the apparent issue of a "don't evacuate" command by RF2 brings up the issue of the possible conflict of authority between the Captain's Part 91 FAR authority and the authority of the Incident Commander of the ARFF response to a situation.
It's been discussed recently here on other threads. I think it's the Part 121, not Part 91, pilot in command emergency authority that applies to this case:
§121.557 Emergencies: Domestic and flag operations.
(a) In an emergency situation that requires immediate decision and action the pilot in command may take any action that he considers necessary under the circumstances. In such a case he may deviate from prescribed operations procedures and methods, weather minimums, and this chapter, to the extent required in the interests of safety.