Exactly. Hunters most defintely ran out of mana. Because hunters were #1 DPS in Sunwell w/ gear (lol 1 button macro to the top of the charts) I had a shadow priest in my group by default so mana wasn't much of an issue. In vanilla, it was Feign Death + Drink. So you didn't do 50% damage, you did no damage for a few seconds.
Seriously, focus >>>>>>>>> mana.