I reported this to a GM and got a bemusing reply telling me to turn on War Mode or join a random grp lol. Needless to say those didn’t work.
But I tried what you suggested Nocty. I completed the Assault, handed in everything then went back to the collapsed NPC and I still can’t click the bottle. Did the usual turning off all addons, reload, exit game and still nothing.
You could still be right though in that it’s a bug related to this PARTICULAR assault. I will try and come back on a different assault although I wont hold out too much hope as it would be an assault not related to this quest…but worth a shot right?
Will post back if it works.