Death's Oath and Ancestral Bond

I searched for an answer for this, but didn't found a correct explanation.

My charater triggers 'You take 450 Chaos Damage per second for 3 seconds on Kill' from Death's Oath with the Keystone 'Ancestral Bond'.

The Ancestral Bond Keystone should set every damage I do to zero. I should only be able to do damage through damage instances that are not my character. These are Totems, Traps, Mines and they don't trigger on kill effects. Degen effects like Righteous Fire also deal zero damage with Ancestral Bond. So I don't understand how Death's Oath could deal damage and if it could deal damage how it could trigger an on kill effect, because it would have to be a separate damage instance that is not my charater.

I guess this is a bug or did I miss something?

Screenshoots:
http://imgur.com/a/h0ose

1. Debuff from Death's Oath applied
2. Ancestral Bond Keystone

Thanks for you're answer Raye. I really wasn't sure about how this works.

But if it's not me doing damage why is the on kill effect triggert, it also triggers other effects like frenzy/power charge on kill.
In case of a trap it does not trigger on kill effects, because it's not me killing the enemy but the trap.

Why does a on kill effect trigger if the items degen kills the enemy and not me?

I use Spell Totems with Righteous Fire. They don't trigger on kill effects, but the chaos aura from Death's Oath does. This is very annoying, because both Righteous Fire Totems and Death's Oath Aura kill mobs near to me simultaneously. I always degen because of this and it makes no sense to me why it works that way.

Interesting, maybe it's the same bug as this DoT bug. Good to know that it's not an intented behavior, because that would be really confusing :D