With regard to domestic carriers diverting, in fairness it is very doubtful they arrived at ROV with close to 4 hours worth of fuel and probably did not have the option to hold. Right or wrong, FZ at least had that additional option and chose to exercise it without compromising any subsequent decision to also divert.
The forecast at the closer diversion fields to ROV also wasn't great, so not very many appealing options that particular night.