when the big bowl of wrong goes bad

As a freelance software developer, it's often happened that I'm asked to take over the work that somebody else has, for one reason or another, left behind either incomplete or in need of ongoing maintenance. As with any endeavor where, on the short term, one is required to set aside one's preferred methodologies or otherwise accepted best practices in order to accommodate the style of the other person, the thought of "this guy is a fucking nutjob" crosses one's mind often, pre- or proceeded by a machine-gun rattatat of creative cursing, head-banging on the desk and certain promises made to oneself that, if paths were to cross at some point, his ass will be royally kicked.

It does not, however, happen that often that said predecessor is quite literally a homicidal maniac.