GD
Green dot only comes into it as a coincident speed at that weight. If you control SPD from the FCU to below GD, whilst trying to avoid a flap\slat overspeed (which may only be a very small number of knots), you quite possibly end up clean below GD and maintaining that SPD as it's selected. Calm conditions at that weight and pulling SPD 230Kts, the auotpilot or ace pilot doing a fine job and all is well. That's all I was trying to say.
As I said, you can fly a SPD below GD clean, Mr Airbus, as told to me by a nice man at TLS, don't recommend it for the obvious reasons !
Cheers