Glich involving the doppleganger?

Hello.

I was fighting the doppleganger as a N/Me using the sacrifice health trick, and then the fight resulted in both of us dieing. I didn't get credit for winning, but it said "Quest Added: Mesmer's Path". This quest did not show up in my log. Anyway, when I actually won, it did not say this quest was added again. Was it supposed to be?

You were am N/ME when you fought him.

It will always do an update to your secondary so that you don't have to do the quest to be able to switch back.

The sacrifice health trick is so that he kills himself, you aren't supposed to use them yourself.

After you fought him and didn't get credit for the win, did you find yourself in Dragon's Lair (and 50,000xp richer)? If so, then you won.

You auto-pass the profession you are so you can automatically swith to it without any quests.

It isn't a glitch - it wasn't ever suppsoed to be in your log.

Oh oh, of course I'm not supposed to use them myself :P
He just actually killed me with the skills as well as himself.

And when I died, I wasn't in Dragon's Lair. I returned to the outpost right before the fight. I did, however, beat him in the next fight. I was just wondering if the quest added thing was normal.

Oh well then you used the wrong sacrificing spells
Don't put the ones in that can actually allow him to hurt you. But as you've already beaten it, the point is moot.

Assming you both died simultaneously the game can act a little strange I guess passing you through the Mesmer's path as if you won, but not advancing you. I chalk it up to timing.

Necros can beat their dopple in like 10 seconds with ONLY 2 skill on your bar:

Awaken the Blood
Verata's Sacrifice

verata's sacrifice is only available at copperhammer mines and beyond.... so if you are playing the game through like a normal person, you'd not have access to that skill yet.