Well yes. But if you choose to be a medical professional, that comes with the job: anything you do is a legal liability. That’s a given. After that, a doctor can choose to perform an act for free or not - and quite frankly, if I had gone through 7 years of medical school, I wouldn’t work for free either.
Matter of fact, anybody who performs any medical act engages their responsibility. I learned that when I had first aid training: if you choose to mess around with someone’s body and something goes wrong, you’re on the hook. And even more so if you weren’t qualified to do it in the first place.
That’s why I’m always amazed that there aren’t more piercers and body artists in jail. Them guys tread a fine line.