@George-K
Any doc can purport to be qualified to treat any condition. If the results end up being unfortunate, let him bear the consequences either in court, licensing body, or public opinion..
Yes, I have seen just that with my late father. When he and his wife moved to BC in their retirement, they connected with an MD who had numerous geriatrics as regular patients. In any case my father’s wife really liked him. My father not so much, in fact he didn’t think he was all that great and would only refer him to specialists as a last resort.
To make a long story short, it all came to a head in 2003 when the MD refused to order a colonoscopy for my father after a few months of ongoing big issues down south. He concluded it was amoebic dysentery and treated it without result other than a worsening of the problem. I raised hell with him over the phone a said I would drive my father to Bellingham Washington and pay for the colonoscopy out of pocket. The doctor relented and agreed to order the procedure. Yes, there was cancer and a specialist was then engaged. Luckily it was slow growing and located convenient for surgery. Surgery was successful. After speaking with the surgeon I had yet another go around with the MD over the phone. The surgeon however was not impressed with what he discovered and went after the MD. Turns out that that the MD was not a specialist in geriatric medicine, but rather an OB/Gyn with a less than stellar record with his peers. He soon closed his practice and moved elsewhere. A bit like the surgeon you described.