It's only illegal if someone prosecutes. (See American Government)
It's unlikely a defunct company, run by a convicted guy, employing a person that didn't sign an employment contract (and by extension, a Non Disclosure Agreement) would pay attention to this, much less go after him.
It's unlikely a defunct company, run by a convicted guy, employing a person that didn't sign an employment contract (and by extension, a Non Disclosure Agreement) would pay attention to this, much less go after him.