I had a coworker once that used a library of his in all of the company's main applications but kept it out of source control. If you ever asked to see the code,

I had a coworker once that used a library of his in all of the company's main applications but kept it out of source control. If you ever asked to see the code, he would say "what do you need, I'll do it for you?" One day after chasing a bug for hours, I begged him to allow me to see the code and he refused. I calmly walked back to my desk and Reflectored it and found the bug in less than 10 minutes.