Well to be fair, the author says the user specifically identified the speed of submission as suspect. If that’s true (and I have no reason to doubt it, there is

Well to be fair, the author says the user specifically identified the speed of submission as suspect. If that’s true (and I have no reason to doubt it, there is a long running UX trope about adding artificial delays because users find fast results untrustworthy or unsettling in some way), it’s possible they didn’t fully understand their own psychological reaction: it was fast and it provided feedback in an unusual way. If my comments (posted to the site before coming back to see the HN discussion) are reviewed and pass muster to be posted, they’ll reflect these thoughts as well.