Geoffers,
You are quoting (correctly) from the EASA RFM. The CHC ECL however, includes a further step prior to LAND/DITCH IMMEDIATELY as follows:
If warning remains illuminated and there are positive signs of fire other than the fire warning:
LAND/DITCH IMMEDIATELY
and,
If warning extinguishes, or there are NO positive signs of fire other than the fire warning:
Land as soon as possible
This is hardly a new issue and certainly not exclusive to the AW139. ECL's for many types, for many years have advocated land/ditch in the event of a persistent fire warning, and it's always been up to the aircrew to make the "best" decision commensurate with the circumstances and not just blindly follow the checklist regardless of the consequences.