A responsible journalist can't say directly that Sacks was a confabulist but they can point out facts and allow the reader to infer. That's what the article does. There are many facts in the article that are relevant to the title in this sense (the prime number twins, the journal entries about Hat, etc.).
I also don't agree with your interpretation of what the article is trying to paint Sacks as, though of course you are entitled to it.
I think the the point of the article is to articulate what Sacks himself said:
> "As Sacks aged, he felt as if he were gazing at people from the outside. But he also noticed a new kind of affection for humans—“homo sap.” “They’re quite complex (little) creatures (I say to myself),” he wrote in his journal. “They suffer, authentically, a good deal. Gifted, too. Brave, resourceful, challenging.”"
I also don't agree with your interpretation of what the article is trying to paint Sacks as, though of course you are entitled to it.
I think the the point of the article is to articulate what Sacks himself said:
> "As Sacks aged, he felt as if he were gazing at people from the outside. But he also noticed a new kind of affection for humans—“homo sap.” “They’re quite complex (little) creatures (I say to myself),” he wrote in his journal. “They suffer, authentically, a good deal. Gifted, too. Brave, resourceful, challenging.”"