Game Mechanics: Zoning with low health/unconscious results in full health

[Bardolap]

I thought that I may have noticed it during beta, but couldn't recreate and isolate exactly what had happened. I know I was VERY low health (less than 5 hp), as I bareley made it out of Crushbone alive. I've seen it twice now since launch though. Once I had 2 HP and the other time I was actually -4. After zoning into Gfay, I had full health.

Don't have much more info than that. All three times happened zoning from crushbone into gfay. All three times with low (or negative) hit points.