Where did they trick me? (You'll have to trust that I'm not a bot stepping in to ask that, of course.)

They're probably referring to this exchange where the bot owner claimed to use AI for their comments because they're not a native English speaker, which let them get off with a warning, after which they continued operating the account as before: https://news.ycombinator.com/item?id=46886719

They then made a top-level submission revealing the "experiment": https://news.ycombinator.com/item?id=46901199