First of all, we don't pull meters. That's a dying practice and isn't even taught anymore. Around here we don't have outside disconnects. I'm not going to go searching for a panel in a large fire and its certainly not going to be a find the panel first then fight the fire kind of thing. I would absolutely shut off a breaker if I knew say that an AC unit was overheating but not if it was on fire and I have to protect exposures first. When somebody does get to the panel, we shut off the main, not the branches. That's an investigation thing. Usually if the the fire is big enough to warrant needing the power shut off, the utility is pretty good about getting out there quickly and diverting or switching the transformer.
As for the nozzle thing, you never fight a fire with a fog nozzle set to fog. Its a good way to get yourself steamed. The fog nozzle is good for hydraulic ventilation and mopping up but otherwise it stays pretty much set to straight all the time. We also use stacked tips which are straight streams of water too. The nozzles are not designed with spraying into live circuits in mind.