Gnow,
Your SOPs are trying to keep things simple, but there is a danger in classifying events purely in terms of 2 options: " if there is a fire, do X,, if no fire, do Y." If you experience a straightforward flameout, then generally it will be safer to not touch anything below 500'. If you have something more catastrophic, (which could include fire, driveshaft failures, runaway up, turbine separations, etc,) then it MAY be prudent to take some action below 500'. I am guessing your SOPs do not mandate action below 500', in the event of fire, they just don't forbid it! That is the decision the captain gets paid for!