hunter pet auto-aggros successor (repop) mobs

Was killing Keeper ghost for AS quest. Sicced pet. After the Keeper dies, it auto-respawns immediately (which is convenient). However the pet then immediately attacks the repop, as if it were the same mob, despite being out of range and not attacking us. Pet was on defense, not aggro. Replicated this several times. Technically the repop is not the same mob, so a pet on defense should not attack without orders unless the mob attacks first -- which it didn't.