Rathbreaker Bug??

Bug Report ID: #1480505060

I saw the same thing today in Act 2 normal. Rathbreaker was using special moves as normal at first. After running out of the arena, he ran back up, started healing, and became inactive even when attacked for 30+ seconds. During this time, I killed the spear thrower monsters on the cliffs above (Arc can auto-target them if you aim nearby). After a while, Rathbreaker became active again, but when fighting him he only did auto-attacks; no slams, no arrow storms, and no summoning large packs of hyenas (although a group of them did come up the hill after he died).

I fought Rathbreaker in a party of two (sorceress + with with minions).

On a side note, I'm uncertain if Arc being able to target and kill the spearthrowers on the cliffs is also a bug or not.

It happened to me today. Act 2 normal.
Here is a video I captured : https://youtu.be/VlqJLEymVgc