Question re: automatic rezzes

[zombietychus]

I am experiencing what I assume is a bug, but it might just be a game mechanic I don't understand: when playing my low level bard, I find that on occasion, when I should die, instead I am resurrected at full health after being knocked to the ground. Is this normal? It only happens a small fraction of the time, but has definitely happened at least three times on the way to level 10.