It wouldn't really be illegal at all imo. It's his invention at the EOD, and he could do with it whatever he wants. Thats the beauty about living in America, pretty much the freedom to do whatever you want with your own stuff. Do not take my advice as a for sure thing, hence why I asked anyone to point me in the direction of some good DD on the company i.e. who owns the invention, hows it being infringed upon, etc etc.
I enjoy doing DD on many stocks I own and do not own... All my thoughts are my own and you should do your own DD before investing :-)