Warrior selfheal is fine (especially with 2pT15 and 2pT16). I'm pretty sure Dark Animus is soloable as a warrior, tbh.
There's at least one "Raegwynn is a super soloer, he finds clever ways to do things" on this thread and many more along the several forum/websites related to wow. It's a bit frustrating when he just replicated a stratgy that was given to him.
Of course he gave credit to Snowball, but since he's more famous, most people only heard of the fact that "Raegwyn killed Dark Animus", which is sad.
Edit: To be clear on the "how", when the Anima Orb explodes, all the golem don't receive anima at the same time. Anyone who has tank the fight knows that the golems at the bottom of the stairs get anima before the golems at the top of the stairs. Basically, you have to kill one of the golems that recieve anima first before the golems at the top of the stairs recieve anima. That way, the anima will jump from the golem you've killed to a golem who has yet to receive anima.
The "bug" is that when the Anima Orb explodes, it can only fill small golems giving 4 anima to each small golem. It doesn't check if a golem has already some anima.
It's a very clever way to avoid the soft enrage. It may be seen as an exploit and probably would have been if it had been used during progress, but as far as soloing is concerned I think it's legit.