Very sorry to here about your loss.
I have seen this on Sim Jet a few times over the years. I have seen it happen in flight! The engine has flamed out but the pump still runs.
One model it happened on was a friend of mine's F15 he was landing after flame out and we saw flames licking out of the wheel wells! When i got to it i could here the pump STILL running!
Some quick work with extinguisher saved the model.
A servo operated isolator would help.