Modern denialism tends to be more centered around climate change- whether it is occurring, and what the impacts will be in the near and long term, and how to respond. Many physics people (who worked on high energy particle physics, etc) have looked at the claims from the various climate change promoters and found the source evidence to be less than convincing. If they articulate this, they are often described as denialists. Here's an example: https://en.wikipedia.org/wiki/William_Happer
a.n.y.t.h.i.n.g
I've watched very experienced, top school trained MDs freeze up and begin to stutter, as they've just realized they said something their lab chief does not like.
Coincidentally, that chief writes treatment guidelines and consults the FDA, and is probably one of the most powerful physicians in the profession.
Medicine is a very hierarchical top-down command structure type of field.
Did he end up permanently losing it?
This is precisely what modern science is (well, a major subset). The competition for grant funding and attention space is extremely intense.
I agree there was no "alzheimer's cabal" but it's not uncommon in science for the prevailing mainstream position to (intentionally or otherwise) suppress alternative opinions ("extraordinary ideas require extraordinary evidence" is often used to maintain the status quo).
One of the important issues is when an idea ends up dominating funding. If you have a legitimate alternative hypothesis but can't get the funding to run the experiments to provide that extraordinary evidence, you'll fail to convince people. The people who get the most funding are the ones who are the most competitive, not the smartest, or the rightest.