Diana Passive Inhibitor Bug

I found a minor bug with Diana's Passive.

I was playing a Normal VS AI Bots game (normal difficulty) with the Valkerie Diana Skin.

Normally her passive isn't supposed to be procced on inhibitors, however when I get my first 2 stacks on minions and attack the inhibitor on the third attack the passive is applied and deals the bonus magic dmg to the inhibitor + surrounding area.

Really don't mind, because it can be used somewhat to alternate between hitting minions for farm and still damaging the inhibitor, but a bug nevertheless