As a CS undergrad, I picked up a spot of freelance work.
The task is small, should take under 3 hours. I tell him it'll be ready by tomorrow.
1 hour in...
Him: Is it done yet?
Him: What're you working on?
Him: Okay cool
**60 minutes pass, wherein he asks me if it's done & what I'm working on every 10 or so minutes**
When I finished (read: had something that met specs and compiled) I told him, yes, I was finally done, but I hadn't tested it whatsoever. Use at own risk. He says okay, send it over.
So of course he puts it to the test on a running, live, important machine.
Of course, what I wrote was a plugin for a single-threaded daemon/server program, which was the sole purpose of the machine.
And, of course, it hung during some loop I had apparently stopped writing halfway through- probably because he interrupted me to ask for a status update.
Not worth the 50 bucks, never again.