Contractor position: for doing math using company resources. Basically, they were looking to trim their budgets and us contractors were the best paid. In addition we'd already got the job done, just waiting for term to end. I was so mind numbingly bored that I started doing Project Euler, first at home then eventually at work to fill the time. That was 'just cause'.

I also suspect that one of my solutions wasn't well appreciated. There was a job that analyzed historical data and generated a projected date (or risk I can't exactly recall) that was very complicated and took way too long to run. I cooked it down to one database query where all the data was anyway to get an answer in a couple of minutes. It took a long time to make the query, needing multiple updates (PTFs) of IBM DB2 to extend limits I was bumping into and working around with guard condition heuristics to narrow the search space. The single query was about 3 pages long. There were timeline diagrams showing the areas that each heuristic was narrowing or excluding but not simply enough.

I remember when the guy who had to deliver the news, but obviously didn't make the decision had the talk with me. My reaction was "Fantastic!" as it was such a relief to escape boredom early.