On: Tell HN: Somebody implemented something I wrote a ...

[nick__m]

You would have to randomize the error when the wrong password is inputed and ensure that for a particular username the returned error is invariant. Else an attacker could infer that when you get a different error you have a correct password.

[ezekg → nick__m]

The bad password error would only be sent if the second factor is valid, though.