First of all, don't trust what people say. 95% of them are probably bragging about something they didn't even manage to do, or might have done but with a lot more trouble than they want to admit. People's precious virtual egos do stupid things.
Now, for the actual fight. I suggest you check the
comments on Wowhead for that particular boss. Always check the last ones, as they're the most recent and have the most chances to help you. That comment by Keyblayde seems reliable and, if I remember the layout of the place correctly, might be the right trick to pull this off.
In addition to what he says, I'd suggest popping Innervate after the first healing session so that you are still full for the second. You can also keep it for the second session if you have enough mana left after the first to shift and heal again when you will need to.
Remember to pop all your cooldowns on the Raptor before he goes Frenzy and use that opportunity to jump off and heal, and/or kite him while he's in Frenzy as much as possible.
Haven't tried it yet myself, not even being 80 yet, but it sounds feasible.