Went to TK with 4 guild mates, got to the final phase, all but 2 people got MC then KJ bugged.
He remained like this until we all hearthed and came back in. 
He mentally snapped, understanding that you will farm him for another 15 years. BTW he is Kael’Thas aka KT, not KJ, who is last boss in Sunwell raid.
Think he ODd on his magic