I think my point is still being missed.
I understand evade mechanics and boss resets.
The bug is that the companion can still pass through a CLOSED DOOR, and the boss can follow. THIS is what causes the reset.
The companion (or the player for that matter) should never be able to pass through that barrier and cause the boss to reset.
You're using a tank companion for this fight, yes? A simple workout around is to use a dps companion. At level 41 it's not like you really need a tank for this fight. If you use a dps companion Ortol will stay on you and won't push them through the door. Yes, it's annoying that tank comps bug the fight, but the workaround is a dps companion.