Game Mechanics: Enchanter animation able to hold agro over a PC

[Tenlaar]

Yesterday, while I was playing a bard and grouped with an enchanter in N Ro killing scarabs, I noticed a couple of times that after the enchanter's animation pet had been beating on the scarab for a while and it was lowish health I was able to get into melee range (even to the point of standing inside the scarab) without it turning on me, even after I'd been playing Chords of Dissonance.

I don't know if this is something to do specifically with animation pets or if it's something known but it seems worth mentioning.

ETA: And now that I think about it, I'm also not sure if it only happened once the scarab was under the health percentage when a mob that runs would have started running.