Please don't listen to all of these folks who are trying to bring conflict into your life. You did something interesting, and learned a lesson about how big institutions actually work. It is a great story, and one that you can tell your friends.
The easiest path forward is to do what it takes to graduate, it sounds like you are one quarter away. Smile, play nice, help out where you can. Get everything in writing.
Definitely TALK to a lawyer and have that in your back pocket. It is likely there is some sort of legal aid through the law school and you can. However, only use this as a last resort. It would be no problem for a university to drag something like this out for months or years and you will be left without a degree.
That's reasonable advice if he could cease to work on his project and status quo were resumed, but from his telling of events, it sounds like they're saying he can't study at all unless he works for them for free. Such a scenario would be extortion, and is worth taking the stand on IMO.
There is already conflict in his life at this point. The question is how best to resolve it. The school is in a position of authority and is telling the student that after spending tens of thousands of dollars at his school, he can't register for his final quarter necessary to graduate, unless he provides additional free work for them. This absolutely should not be tolerated.
Everyone in this thread is simply suggesting he talk to a lawyer. The lawyer can help guide him on the next action to take.
The easiest path forward is to do what it takes to graduate, it sounds like you are one quarter away. Smile, play nice, help out where you can. Get everything in writing.
Definitely TALK to a lawyer and have that in your back pocket. It is likely there is some sort of legal aid through the law school and you can. However, only use this as a last resort. It would be no problem for a university to drag something like this out for months or years and you will be left without a degree.