5 attempts in a row now, heorot keeps glitching into the floor while charging, proceeding to one-shot me with blizzard. Attached is a video (bug happens at 24 seconds):
Here is my log file from this session:
Player.log (1.2 MB)
Some speculation after some more attempts: it seems heorot is colliding with my totems, would also explain how this is not a widespread bug (it happens to me on every attempt). Will try to avoid placing them near him during charge and report back.
After even more attempts, i strongly suspect he is colliding with my totems. The bug does not occur as long as all 3 of my totems are at his rear as he is charging. Can provide more footage if needed.