I ran into an equally weird bug later in IC in Kyne. My 15th character is about 49 and 1/2th level so I thought I'd roam around in IC while the mobs are still comparatively scary for a bit on an AD toon.
Ran into a DC player and we ganged up on the mobs. My bear started messing with him so I ran off to heavy attack some other cluster of mobs to heavy attack them and take the pressure off. All of a sudden audio went away except the sound of being slammed repeatedly in the head with aluminum sheets sporadically, and all skills except movement and weapon swap froze. I could drink potions, dodge roll, block but not attack. The mobs looked normal then shuddered like they were in lag and were gearing up to macro slice the crap out of me. Game froze for about 30 seconds then came back right as the mobs were finishing me off, and all the audio returned in a rush. I wish I had a video of that.