The electrical disturbances don't need to be introduced into the electronics directly though - if the flare induced enough disturbance into the national grid, then all sorts of strange induced currents could appear on your mains voltage, and wreak havoc with inadequately filtered power supplies.

We rely on mains power to arrive at a nice even 50-60Hz, with the voltage varying a few percent. Sensitive electronics are designed to filter out this low frequency, but higher frequencies may well pass through into other circuits that weren't designed for it, with unknown consequences.