A few things came into play. I have a strong distaste for Fox's politics and lack of journalistic integrity, and I viewed the founders' selling of the property to them as pure greed move, contrary to the intended educational and non-partisan nature of the game (which was about political races). But in spite of that, I felt a professional obligation to assist in the transition, maintenance, and even continued building of the project. Once I had gotten the backend over to them, along with the compiled Flash SWFs, I let them know that I would be available to them at my usual hourly rate.
Part of this just comes down to the nature of large corporations. They were never interested in hiring an independent outside party, under any circumstances. At first, before they realized that their team would need my help, they simply declined my offer.
From my perspective, they were of course free to rewrite or extend for whatever uses the art/product they had purchased. But then they started calling me demanding source code, and explicit in that demand was the contract they wanted me to sign which would have given them ownership rights to it. The problem as I explained was, a good deal of that source was my own, proprietary stuff. Big parts of the game platform shared code DNA with other projects I was working on for other clients. I don't double-bill my time, but that meant each client was coming to me because I had developed a platform and a whole suite of GUI components in Flash that could be rejiggered to meet other needs without having to code everything from scratch each time. That's what made me cost-effective and quick; it's part of the reason I was hired, and my clients understood that when I did code for them, some of that DNA might get reused in unrelated projects. So not only would I be giving away rights to code which other clients had rightful use of (potentially exposing them to lawsuits from Fox), but I would be left without the dozens of modules and packages that made up my toolkit, which was my livelihood.
And all of this they expected me to do for free, in exchange for a contract which would have made me their employee at half my rate. I certainly had no intention of ever becoming a Fox employee, even if they tripled my rate. This fact seemed to elude them.
So, it's not really how they asked - although that was offensive, and their attitude that they had all the power in the situation certainly didn't make me keen to help them. It's that what they were asking for would have destroyed my career. And besides that, I felt I didn't have a right to sell those packages at any price. They refused to acknowledge that they would have to share the code with my future projects and other things already in the wild, and that they had screwed up and didn't own what they thought they did. That they had bought the game, not the platform. If they had asked me for source and not demanded the rights to it, with or without paying me to help them transition, the game might have lasted a long time. Instead they tried to decompile it, couldn't figure it all out, left a half-broken version up for a couple weeks and then abandoned it.