It is a part of fail-operational system, so definitely much less than 1:10^6.
Airbus says: "If no FLARE at 30 ft and visual references not sufficient, execute a go around."
To call "No Flare" by PM is part of the trained task sharing. Unlike "No LAND (at 350')", it needs to be verbalized because PF is not scanning the instruments at that stage.
"Can no FLARE situation happen on a fail-operational system without triggering the AUTOLAND warning" - that would be a good question.
Last edited by FlightDetent; 9th April 2017 at 09:38.