mangos one Hunter pet in defensive mode with multiple attackers returns to hunter after first one dies

Summary: While hunter pet in defensive mode is being engaged by multiple enemies, after the first one dies it begins returning to the hunter as though it has no more enemies in its aggro table. Once attacked by another mob it then attacks that one.

Steps to reproduce:

1. As hunter with pet summoned, put pet in defensive mode.
2. Have pet attack one of several enemies in a small area such that they all pursue the pet
3. Finish killing the first enemy

Expected result: Pet's focus immediately shifts to another attacking enemy.

Actual result: Pet starts running back to hunter unless attacked again, then will attack its attacker.

Discussion: It seems like hunter pets don't have a true aggro table but just a single aggro target. Once an enemy is killed it has no recollection of being hit by anything else. Alternately, it's possible the pet's aggro table is being cleared after any mob death. Instead, any hostile mob that attacks the pet or hunter should be added to the pet's aggro table and removed when the enemy dies, becomes breakably CCed, or evades.