1) In what universe is "Indie/IMG/Solar" a lawful Gallic corp? Especially when the base was NOT yet declared legit by the Kingdom of Gallia, thus rendering it inRP-illicit by default (all base projects should get approval BEFORE construction starts).
Also, I don't think it has been really confirmed that the attacker was GRN.
2) The actual point still not resolved/answered is the question why the base was restored a second time, despit it being destroyed by legit means. Either you fairly restore all "mysteriously destroyed" bases or none, as long as no exploitive means were involved (as confirmed during the first destruction of Brimstone).
Using different measures for different bases/people is simply unfair, as several people pointed out already. And while the base shield/repair system might need some refinement, the system employed at the time of the attack allowed for a good safeguarding of a base with the same means as always: having enough repairs&fuel stocked. This was not the case, thus leading to destruction.