Stuns are Broken?!

[spoil]

https://tinypic.host/i/stun-is-no-fun.oks7j2

Maybe I'm ignorant but I don't think I've seen this before. I cast Color Slant and the text reads "Keljemor is dazzled by scintillating colors" meaning the stun landed and I should have approximately 8 seconds to ponder who the fuck Keljemor is and what he or she is doing down near the Brood Mother camp. But evidently being "stunned" is no impediment to this beast as it continued to beat on me with aplomb. I'm used to high level mobs resisting my stuns, but with the text saying "Your target resisted the soandso."