Levelup has noted in another supplement, is that the effects of fatigue and strife only take place after the encounter they are accrued. So there is no death spiral, you start an encounter with the penalties you are going to have, and those will be your penalties for the rest of the fight regardless of how much additional fatigue or strife you accumulate.All true, but you also need to avoid a death spiral.....
That to me also includes "doomed". Even if you hit that level 6, you don't die in the fight, you heroically battle to the bitter end. Only once the fight ends, do you have your cinematic death. Or hell if a DM wants to be really cinematic, they could have the character continue until the end of the given adventure....but with the knowledge that they are going to die....which could be pretty cool.