An excellent article, if sadly not very in-depth. Definitely a good starting point for people wishing to delve further into the subject of "experts" and the "specialist vs generalist" debate.
To add my own two cents on the subject:
A number of years ago, I was diagnosed with a rare form of malignant sarcoma that, if left untreated for too long, has close to a 100% death rate, and a decently high death rate even with treatment. Three different doctors examined me over a period of a few months - two of them by cutting me open, but each failing to take a tissue sample, relying instead on eye sight - and all three concluded that what I suffered from was a lipoma, a form of fatty mass.
When the first doctor provided me his diagnosis, I went and read up on lipomas, and in particular their symptoms and development cycle. I soon discovered that neither matched what I had, so I sought out the same clinic I had gone to the first time, hoping to speak with the same doctor.
Unfortunately, said doctor was on holiday at the time, and so I was assigned to a "stafettläkare" - a type of doctor that works in shifts at many different clinics and hospitals, never staying in the same place for long, at a ridiculously inflated salary. I presented my findings and conclusions, and after listening to them he dismissed them without offering up any real counterargument, simply stating that it was an asymptomathic lipoma, likewise without offering up anything to support his conclusion. Still, while it was statistically unlikely - and fit poorly with the symptoms - I didn't press the matter, and went home to study up on asymptomatic lipoma.
A number of weeks later, I went back to the clinic a third time and was assigned a third doctor, because the first had apparently retired (having used his accumulated holiday days to effectively get off early), while the second doctor was no longer employed at the clinic. I presented my findings and conclusions to the third doctor (including that there was a high likelihood it was cancer, as that fit both the symptoms and the time frame and development cycle), who nonetheless insisted that it was asympthomatic lipoma, despite overwhelming evidence that it wasn't. Having lost my patience at that point, I demanded to be referred to a surgeon. The doctor told me it was a waste of time, but at my insistence he wrote me a referral.
A week later, I was fortunate enough to get an appointment with an experienced surgeon of the elderly persuasion at a hospital in another town. He cut me open - for a third time - and eyeballed the tissue. He concluded that, while he couldn't determine its exact nature with the naked eye, it most certainly wasn't a lipoma, and he had hard time understanding how any doctor could make that mistake. He acknowledged that my analysis was well done and my conclusions fit the facts, and that there was indeed a high likelihood it was a cancerous tumor. He offered to remove the offending tissue and send it to the lab for testing, an offer which I of course graciously accepted.
As it turned out, the tissue was a malignant sarcoma tumor, and even with the timely removal of the tumor, there was a very real risk I would lose my right leg (as the tumor had been situated in my right knee), as well as a high risk I would develop metastatic tumors in my lungs, which could easily kill me even with extensive chemical and surgical treatment.
Fortunately, the old surgeon was quite skilled, and although I did have to undergo a second surgery - to remove tissue that had been in direct contact with the tumor - the tumor appeared to have been completely removed, and although I still need to X-ray my lungs once a year, there has been no sign of any metastatic tumors.
So, yeah, I am intimately familiar with how "experts" can be very, very wrong, and how you should always study and analyse a situation yourself (assuming you are able to do so, of course) rather than blindly trust authority figures. Now, having a high IQ as well as some previous experience and training in both the medical field and data analysis I admit I have a bit of a leg-up on most people when it comes to "doing my own research", but the importance of it still cannot be understated. Far more important than "previous experience" and "expertise" is, of course, one's ability to identify, study and analyse relevant information.