Oh come on Gruber, it was a tech demo.
"How is what they showed, and the way they showed it, distinguishable from a fraud? The more I think about it, the more strange this “demo” seems."
Denialism of somebody who made a company part of his identity.
It is kind of weird that the broad tech punditry has just accepted Google's demo at face value with respect to what the tech is actually capable of at present.
[EDIT]
For example, Google demoed object removal in Google Photos (https://www.theverge.com/2017/5/17/15654476/google-photos-ob...) last year, and as far as I can tell it never shipped.
[EDIT 2]
If a company in any other industry announced an insane-seeming new technology with a completely non-verifiable demo like this, no credible journalist who covers that beat would report it as credulously as tech journalists have covered the Duplex demo. Gruber is absolutely right that the lack of skepticism around Duplex is baffling and journalistically suspect.
Yup. Isn't playing prerecorded presentations standard operating procedure, to minimize risk of angering the demo gods? Doing a live demo is a really strong show of confidence.
Besides, tech demos are carefully crafted and not a honest evaluation of technology anyway.