EDIT: Removed active character names.

First, what class are you?

Second, I'm thinking regardless of the above, you shouldn't
have hung around after the backstab, much less the following
three rounds. If you would have fled at 74% hp, you could have
outlasted the poison easily. Your standing around cost you 65%
of your total life (the vast majority of your remaining life).

If he hadn't missed his trip attempt, you would have died to
him right there, on the spot, before the poison even hit.

His backstab lagged him two rounds. If you would have fled
immediately, you would have had one hell of a head start.

So in short, the the way it could have been avoided is if you
simply used the flee command. See below:

<100%hp 100%m 100%mv 6226tnl (8.98%)> 
Enemythief steps out of the shadows.
Enemythief's backstab DISMEMBERS you!
That really did HURT!
Poison creeps into your body from an envenomed steel
stiletto.
You feel very sick.
You yell 'Die, Enemythief, you backstabbing scum!'
Enemythief has a few scratches. (He's lagged for two rounds.
That means nothing he enters will go in. until two rounds of
combat have passed)

*****FLEE here would have saved you easy. 

<74%hp 100%m 100%mv 6226tnl (8.98%)> 
Enemythief's poisonous bite mauls you.
Enemythief's poisonous bite maims you!
Enemythief parries your pierce.
Enemythief has a few scratches. (One round...)

*****FLEE here would have saved you as well.
<51%hp 100%m 100%mv 6226tnl (8.98%)> 
Bystander2 utters the words, 'oculoinfra uizug'.
Enemythief has a few scratches. 

<51%hp 100%m 100%mv 6226tnl (8.98%)> 
Enemythief's poisonous bite maims you!
You parry Enemythief's poisonous bite.
Enemythief parries your pierce.
Enemythief has a few scratches. (Two rounds... so he should be
able to do something else pretty soon.)

<38%hp 100%m 100%mv 6226tnl (8.98%)> 
Bystander1 looks at Enemythief.
Enemythief has a few scratches. 

*****FLEE might have saved you here, too.

<38%hp 100%m 100%mv 6226tnl (8.98%)> 
Enemythief's trip misses you. 
Enemythief has a few scratches. 
(Trip, if it hits, would lag both you and him for two rounds,
which works in his favor since he's outdamaging you. So this
would have been bad.)


<38%hp 100%m 100%mv 6226tnl (8.98%)> 
Enemythief's poisonous bite maims you!
You sure are BLEEDING!
Enemythief's poisonous bite maims you!
You sure are BLEEDING!
The Edge of the Feanwyyn Weald

You waited until wimpy kicked in to make you flee. But at this
point, you were already dead.

Good luck!