My reading was that they're suggesting that in so-called two-party consent states, getting a third person in the room (whether or not it's done surreptitiously)

My reading was that they're suggesting that in so-called two-party consent states, getting a third person in the room (whether or not it's done surreptitiously) and then having consent from 2/3 parties makes the recording legal. That's not true, of course - "two-party" is a bit of a misnomer. This feels like dangerous advice.