To me this is a simple enforcing of unavailable/impossible to do/not flexible enough game mechanics.
And since there was no previous RP from neither RHA or the Zoners on brokering a deal in "overlooking" No Firing Zones laws, it seems justified.
Yes, it would be better if the official faction used a FR5, or the GMs gave them a bit more time to respond instead of this weirdness but I believe the GMs are simply acting for the greater good. Otherwise other factions might also get idea of breaking the inRP laws and getting away with it...
Now if the RHA is so butthurt on what is essentially a very minor and temporary incovenience, maybe they should consider RPing a bit more extensively than "gib money or die plox" next time.