[Gameplay] Cull does not work with Overheal

I am not sure if this is intentional or not, but the cull life on hit does not contribute towards the shield made by the rune overheal.

Although it is pretty straightforward to reproduce this possible "bug", you first need to pick a character with no inherent lifesteal and then choose cull as the first item. then attack minions and observe the lack of shield.