Interesting. What you have basically described is a "look and feel" lawsuit which companies never win. There was probably much more then what the article mentioned. The company can not claim your "thoughts" unless they can show it affects their business aspects. Is your idea involved with current revenue production? Did you use company resources to develop it?, etc. etc.

The man probably pitched it asking for a certain reward and they refused.

Then again, he might have mentioned it, they wanted it, he said no and then they decided to bury him in court costs. Hoping he will settle.

I don't know if it is still valid but I recreated a small routine for a obscenly large goverment company. The question of ownership was raised. The boss spoke to the legal department and they ruled that unless the routine gave the previous company an economic advatage over their competition, you can recreate routines as long as you pull it from memory and not from source code.