It appears, although not specifically stated, that Rhonda's brain was donated...if so, it's unlikely the mistake you mention would have happened.

Also, there are other causes of dementia than Alzheimer's and CJD, such as cardiovascular, and without an autopsy of the brain all of these are difficult to tell apart. In other words, autopsy is the only definitive diagnosis, impossible to make in the living.

There are well documented cases of entire families, world wide, who contract early onset actual Alzheimer's, and diet seems to be unrelated.

During the late 80s/early 90s I worked in a research facility that was involved in CJD research, primarily with sheep (scrapie), and we used precautions when handling specimens. No one, as far as I know, has come down with any problems.

And I should mention that my mother, who worked for decades as a meat wrapper in supermarkets, died of cardiovascular dementia related issues at the age of 85.

No one diagnosis fits all.