Because i was playing strictly non-lethal on Hard, and had read that it was enough, but no. If you stun him and throw every single barrel in the room at him - he will still be alive. So yeah, bad advice, board, bad advice. Good thing i picked half a dozen shotgun rounds a couple rooms earlier, that finished him off.
Also, amazed that there isnt a FAQ for pacifist runs yet. Those that exist are pretty much shooty-shooty.
It does work
just not at max difficulty(still leaves him mostly dead) but difficulty only changes combat, stealth is not effected, and pacifist does not count bosses so shooty-shooty is the best way to go so no special FAQs needed.
Throwing barrels has always been a mediocre way of fighting Barrett. So, it was never great advice anyways. Also, most people throwing barrels are still taking shots at him between throwing the barrels, so he does normally die even on the highest difficulty before you run out of barrels.
Just shooting him with the Stun Gun is still the base way of beating Barrett if you don't count the Typhoon augment.
For my pacifist I first did Typhoon (by far the easiest way to defeat first two bosses)
Non-pacifist playthrough the Revolver with exploding rounds + Frag grenades worked well. Stunning him and using gas grenades makes it even easier.
There shouldn't really need to be an FAQ for pacifist playthrough (it's quite straight forward besides the hacking and wallmine quirks), especially if the part you're questioning is boss battle related... because any advice from a pacifist walkthrough seems irrelevant when dealing with those. You have to kill them, doesn't matter how.
I just finished my pacifist run today on the highest difficulty. Barrett is ridicously easy. I beat him within 20 seconds after the cutscene. Hide behind the pillar on the right after the cutscene then spam him with mines (I think I threw 4 before he went down). Like a walk in the park.
In theory there is no differens between theory and practice - but in practice, there is.