I have found it in FCOM 4 - if no flare at 30 feet and sufficient visual contact - AP off and comlete manual landing.
Even with that being stated in the FCOM, I would rather prefer to go-around in such a case.
Usually PIC is PF during a CAT3 approach. The PNF would make the callout NO FLARE at wich altitude probably? I guess at around 30'. By the time the PF realises what has happened, disconnects the AP and flares for landing, you will already hit the runway in a not very favorable attitude.