I can’t loot the quest item Timewarped Illidari Battle Plans. I got credit for killing Illidan and received a ring as loot but no plans.
I re-entered and killed Illidan a second time and still no plans.
I abandoned the quest and picked it up again. I killed Illidan a 3rd time. I got credit for the kill but still no plans.
I have successfully completed this quest on 3 other characters.