Alright, so just now I'm in a Drak'Tharon keep run with another priest. I'm discipline specced and have Divine Aegis and no Surge of Light, he's holy specced and has that vice versa.
Throughout the two earlier An'kahet runs, I had the feeling he was somehow proccing my Divine Aegis of hÃs heals. Just now, during the fight with Novos the lich, this entwinement was proven when I somehow got a Surge of Light buff. I didn't screenshot it, though I should have.
I've paged a GM and am waiting for an answer right now. Thought I'd share this funny bug with you. I'll update the thread once I get an answer.