Darkmoon faire trinket duration x2 in skirmishes(possible arenas + bgs too?)

Basically found this out on my priest today in a skirmish, wondered why the heck I had a 25sec buff from the trinket Sandman's Pouch since its normally only 20 seconds proc duration.

I then went out to test this at some cows in Elwynn Forest just to see if it was actually true, but only to find it was 20 seconds as I thought it would be.

Then it came to my mind that it may be pvp only buff, so I queued for another skirmish to test it again, and once it procced it actually procced for 40 seconds instead of its normal 20sec proc. The buff stays for the whole duration, so its not a tooltip bug.

I have only tested this in a Skirmish PvP-wise, but my guess is that it would also work in a BG or perhaps in a real arena/rbg at max level aswell.

The version I use is 4/4 so I have not tested any other version of it, nor any other of the Darkmoon Faire trinkets since I simply dont have any, so feel free to test it out too .

Here's some pics showing the proc with seconds displayed + one of the trinkets tooltip.