Early on in the pandemic I was a big fan of Dr. John Campbell and I would watch his videos almost every day starting in Jan 2020. When the virus was only known to be in China he was shouting from the rooftops that the WHO should shut down air travel to and from China. He was one of the first voices I heard predicting covid-19 (not yet named that) could blossom into a huge world-wide pandemic. It was like seeing a slow motion train wreck and being powerless to stop it.
IMO for the first year or two, he was one of the best sources of information on the pandemic. He was very pro-science and anti-conspiracy-theory. Then he slowly got disillusioned with the main stream scientific medical establishment, especially by the WHO. In his opinion they screwed up massively over and over because they kept putting politics above world health. Then in the aftermath of the crisis they didn't do anything to fix the system so they would be better prepared and able to act quickly to avert the next crisis.
He had a theory that the reason there was a heightened risk of heart problems after getting the vaccine was because people giving he injection were not instructed to aspirate, by pulling back the plunger slightly after inserting it to make sure they were not accidentally in a blood vessel. A small percentage of injections do go into a blood vessel and this can cause problems with the heart. I'm sorry for some of the vague language but I hope you get the picture.
He was basically stonewalled on this and was unable to get the guidelines for the injection procedure modified, adding a small step that was trivial to do, would cause no harm, and could potentially make the injections safer. He was also a big advocate for taking large doses of Vitamin D to (5,000 IU) help prevent respiratory infections.
He tried to fairly cover the fringe theories, based on published scientific papers and preprints, clearly explaining the results, the procedures, and how much credence the results deserve. I'm a scientist myself (PhD in theoretical physics) and I felt he was really good at explaining all of this. I recommended his channel to almost everyone I knew.
Then he slowly changed. One big factor was his getting fooled by the establishment. The first video of his that I strongly disagreed with came out around mid-February 2020 (I think) covering England's new covid policy. The policy was bonkers. They wanted to expose as many people to covid as quickly as possible in order to build up herd immunity. Dr. Campbell didn't immediately see the stupidity of this and reported on it like it was a good thing. His trust in the establishment was misplaced and he was embarrassed.
That sort of thing kept happening but probably not to the extent of that first SNAFU. By trying to report on the bleeding edge science he kept encountering shenanigans that seemed designed for CYA and to push an agenda instead of follow the truth. It wasn't all shenanigans but his strong faith in medical science was shaken, and probably rightly so.
IMO another big factor in his conversion was a very vocal contingent of conspiracy theorists in his comments. They would praise him to high heaven when he reported on problems with the establishment while still ignoring most of his scientifically based advice (wear a mask, get vaccinated, etc). I have no proof but I suspect this cheer leading helped steer him in the direction of questioning the establishment more and more.
I slowly stopped watching his channel, probably because the information he provided no longer seemed so critically important. Then when I would occasionally start to watch his videos over, say, the past six months they seemed more wackadoodle, and conspiracy laden. For me, your (
@madodel) linking to proof this video of his was misleading was the final straw. Thank you!
BTW: Dr. Campbell is not a medical doctor. He has a PhD in nursing and has written several large textbooks which he is letting people have for free (pdf). He is an excellent teacher.