Mada,
Yes we interpret it differently. The thrust of that statement is that it was confirmed (through smoke or other means) that you had a fire in the first place, and now do not have confirmation that it has been extinguished.
WRT your scenario, with no other indication of fire, I would have the crew standing at stations, arrange a precautionary disembarkation, and be ready to evacuate at the first confirmation of an actual fire.
We have our holds sprayed regularly in Australia and Africa, and subsequent false Cargo Fire warnings have been dealt with in the manuals of three types (all Boeing) in two airlines I've worked with.
I know you are being honest and reasonable with your answers, so I would encourage you to seek clarification from Boeing through your safety department- simple question for them- does Boeing recommend an evacuation in the event of a cargo fire warning with no other indication present or available?
I have my answer, it's in black and white (well, black and blue!!) in my FCOM.