That tone
Simon, you were going OK until almost the last paragraph, then you felt the urge to go with this gratuitous snipe:
"But there'll also be plenty who were impacted, and irritated, and wondering why they give their business to a company that's also experienced flood damage and can't configure routers well enough to avoid this sort of thing."
Maybe you would like to stroll over and show them how it's done?
I am not a customer of theirs, but when one of my suppliers drop the ball I do not shout at them: I offer to help them¹ getting back on their feet so that we both can carry on with our respective businesses. Everyone makes mistakes and we need to factor that into the equation, else we're not running our show properly.
¹ Usually a great way to do this is to leave them alone so they can spend their time actually fixing the problem, something to which answering questions from customers does not usually contribute.