I had a side project that I wanted to make into a side business. I worked with my employer to write up a doc that said they'd have no claim on it and would let me own it. My employer did have the "we own everything you make" in my contract.
One alternative I've thought about, is how can you negotiate your way out of that clause when you start a job (seeing as how it is slipped into the paperwork you have to sign on the first day, too late to not take the job if you've already quit your previous one).
I wonder how most employers would react to a request to have an attorney look it over, and use the excuse that you want to make sure it doesn't interfere with any non-profit volunteer work you do.
They fired him for just asking? Then they're horrible, and he's better off far away from them. Most employers are not actually cartoon villains and will be reasonable.
He may be better off in the long term, but short term unexpected unemployment hurts. Can hurt long term too, since you will have to take whatever job you can get as soon as possible (unless you have enough savings). And that job you get may not be at the same point as you were in your career progression, since many employers prefer to hire someone who is already working.
