"No." is a perfectly reasonable response as well, especially since in this case, GP was fired on Monday anyway.
All relationships need healthy boundaries, in this case, their relationship with work, and work's relationship with them, is unhealthy. If online research about healthy boundaries isn't enough, I recommend seeking a professional's advice (like a licensed therapist or psychologist).
No psychologist is going to right wrongs that need to be addressed through legislation.
Rights have been stripped from individuals and workers. We need a massive redressing of the “corporate” world. Workers rights matter. We’ve got companies that are too big to fail being bailed out by the government meanwhile companies can schedule you for just under the minimum requiring benefits but still take up as much or more of a commitment as a full time position.
All relationships need healthy boundaries, in this case, their relationship with work, and work's relationship with them, is unhealthy. If online research about healthy boundaries isn't enough, I recommend seeking a professional's advice (like a licensed therapist or psychologist).