SOPs cover most known happenings. However, they simply do not, nor can they ever cover everything.
The closest that I (and my crew and the contents of the aeroplane) ever got to dying was in a situation which was neither covered by SOPs, nor was there a procedure in the Emergency Checklist (I think you call it the FCOM nowadays), nor did I have time to do extensive reading, nor was there a precedent to fall back upon.
Fortunately, I was trained to think outside the box and so it was that we all survived.
SOPs simply cannot ever cover every eventuality.