Caster mastery and delve caches.

I noticed that if you have the caster mastery: 25% chance to open nearby Chests when you Cast a Spell, the delve flare caches do no grant you flares if the spell opens the caches.
I do not know if it is only the "howling den" node that has this bug because of the guaranteed caches, but i have video evidence for it if needed.