As to BM, I talked to my malpractice insurance carrier about doing BM exams. The underwriter told me they’d cover me for a dozen exams a year but, if I had a single claim on a BasicMed patient, they’d “non-renew” me for everything. That’s “claim,” not “loss.” An AME goes over an FAA-mandated list of conditions and certifies that, as of this date, this person doesn’t have any of them. For BasicMed, a doctor says, “It is my opinion that this person is safe to pilot an airplane.” That’s potentially a very different type of liability, pointing to the essential differences between clinical medicine and administrative medicine. It just hasn’t been litigated; it’ll be 10 years or more before anyone knows what the actual malpractice implications of BasicMed are. I suspect it’ll be a whole lot of nothing, but I don’t want to be the test case.
I agree the untested nature of basic med liability is a big concern. Generally, the standard of care for malpractice is to be performing care that is at least as good as the "typical" physician doing what you're doing. If you're an AME doing an AME exam, what you "should be" doing is very well laid out, and so regulated that it's an easy bar to hit. There hasn't yet been enough litigation around Basic Med to establish "typical." Since Basic Med was originally advertised as "your personal PCP can do the exam," will you be found negligent if you don't know the patient as well as a long-time PCP? Or is AOPA's "it's just a CDL" going to stick?
In my mind, it's even a bigger concern for a doctor who is also a pilot. It's all too tempting to come up with worst-case scenarios for a Basic Med malpractice case, but this one is pretty easy to imagine:
"As a pilot do you know that running out of fuel is a leading cause of general aviation accidents?"
"Yes."
"And as a physician, you signed this pilot off for basic med, saying he was safe to operate an airplane?"
"Yes."
"And didn't that pilot's wife just testify that while he was filling out your intake form, the pilot told your nurse that he is bad with numbers?"
"I did hear that."
"So you, as a pilot and physician, think that someone who is bad with numbers was safe to calculate the fuel burn in a 5 hour flight with changing winds?"
"..."
In some ways I think it would be easier for a physician who isn't a pilot: "Well, the pilot gave me this form from AOPA that says it's just like a CDL exam, so I did that and they checked all the boxes." Suddenly, you're renegotiating the "standard of care" to be a CDL exam, which you would probably get away with.
In some ways, Basic Med is trying to have it both ways (to describe it generously) or a bait-and-switch (to be less generous). It's billed as "people won't be scared to go to the doc anymore, because their primary care doctor, who knows them best and knows all of their conditions and treatments, and can really assess the pilot's safety, will be the one to work with them to get everything treated and then approve them to fly." But then it's used as "make sure to go to a 'doc-in-the-box' that doesn't have access to your real medical records, and get signed off. If anything goes wrong, don't worry, they can't disapprove you, just go to another one."
Overall I think Basic Med is definitely a good thing, as it limits the becoming-ever-more-ridiculous SI process, the permanent denials, etc etc. But I also think that a lot of basic med proponents try to have it in all the good ways: "great because any doc can do it," "great because your primary care doc knows you best," "great because there's no more liability than a CDL exam," "great because there's never any denial," but those won't all turn out to be all the way true at the same time. As a pilot, it's great. As a physician, I don't think I'll get involved.
Personally, I would feel super comfortable doing basic med exams for long-term primary care patients, but super uncomfortable doing basic med exams as a one-time visit. (And as an anesthesiologist -- but at the opposite side of my career to OP -- I don't have any long-term primary care patients.)