As someone who runs his own consulting business, if I had clients who didn't know what they were doing and abusive towards me, I'd drop them in a heartbeat. The original poster on reddit isn't going to garner any sympathy from me.
I've kicked them to the curb as soon as possible, but not before sending them their source code (at least up until the last commit paid for), server passwords, backups, assets, and whatever else I can find.
I've never, ever, deleted anything or brought a server down just because I was angry at them. And thank goodness too, because half of the time they come back after they've had a chance to cool off.