>>...A cargo fire, or any fire for that matter is one of the worst things that can happen in an aircraft. If it is serious enough to declare Mayday, it is serious enough to get your ass on the ground as soon as possible, or even faster...<<
Amen brother, amen.
Cargo fire detectors have been known to be unreliable in humid climates, at least one incident was blamed on durians in the hold.
Still, even a third world airline like EK should have land ASAP as the first course of action. Let the geniuses on the ground figure out what happened.
AC, SR and others have learned the hard way about inflight fire warnings.