Kelvin wrt to the aircraft returning to service.
Hold Smoke detectors have signalled a warning on several occasions because of the gas given off from fruit or vegetables...no fire risk but that is unknown to the crew. SOP dictates firing the extinguishing bottles which in my day would render the detection system unreliable.
The only safe way is to land asap or even ditch but we had a procedure where the flight engineer would go down the back and monitor the floor temp above the hold with his hand.
I was at a presentation where the skipper had similar with a 747 over the South Atlantic...his first emergency airfield refused him landing clearance and he ended up diverting to a military base whose visibility and cross wind were way outside of limits.
He evacuated in near gale conditions using the slides with the normal pax injuries to discover that it was "only" a problem of ripening fruit.
Whilst we practice in the simulator it's not the same conditions as in real life especially as it might be in the middle of the night and you've had the squirts for two days. Saying that we lost a captain on the sim with a heart attack.