Is anybody aware of published analysis of this interesting construction, which seems to require what I will loosely term swear words to work? I believe I've only heard it in British English:
A1 - Dave got a job at Roche.
B1 - Fuck off did he! (=No he didn't; I don't believe you)
A2 - Whales are fish, you know.
B2 - Bollocks are they. (=No they aren't)