Gangplank Series 1 Eternal Bug [Gameplay?] [Client?]

This is a bug with an eternal; I'm not certain whether this fits under [GAMEPLAY] or [CLIENT]

Gangplank's series 1 eternal "Plunder" does not track gold plundered via shooting barrels- it only tracks gold plundered by directly shooting minions.

3 of 3 Gankplank games with the eternal equipped confirm this.

Steps to reproduce:

 1: Play Gangplank with his Series 1 Eternal.
 2: Q a barrel as Gangplank such that you kill some minions and get some gold from Parrrley.
 3: Look disappointedly at your unchanged eternal.

This is 100% consistent.

Here's a screenshot where, because of this bug, I have more plundered gold than is being tracked by the eternal: Link