ToC 5 HC -> Black Knight bugged after wipe

So I haven't encountered this case for two straight days because I haven't died on it but today our healer accidentaly died on a ghoul explode so we wiped and after the wipe something was wrong with the boss.

The initial spell that was casted on the argent tournament npc was casted on our tank, we managed this by him using divine shield but other spells were doing rly insane dmg. The spell dmg stack debuff was stacking for some insane percent and dots were ticking for like 20k+ a second. We even tried this with 3 healers and we couldn't survive it (imagine that with all 4.2k+ gs), bursting phase 1 that fast was just not possible.

P.S: I see what's the real problem in the scripting: Phase 3 spells [Marked For Death] and [Death's Bite] are used by boss in phase 1 which makes it impossible to do...

I had this bug happen once, but we overcome it by running out, setting difficulty to normal and then back to heroic. That way he reset back to normal state