You can't, but you can notice that they're being incoherent if they simultaneously claim to know little about the future and to be able to set strong lower bounds on technology development times.

My mistake; the original post doesn't distinguish between the colloquial term "overconfidence" and "overconfidence" as a term of art in psychology. In the early cases, I meant "overconfidence" as a colloquial term meaning "excessive confidence" — that is, a degree of confidence not justified by one's available information. But later, I used the term to refer to the overconfidence effect, which (as far as I know) is only ever measured in the context of multiple judgments.

I'll try to think of the best way to fix the original post, and I'm open to suggestions!

Edit: I think I've fixed it. I've removed the accusation of overconfidence, while still saying that it might be part of the problem. I've also added a footnote explaining that I've edited the original post to correct the error.