I guess some of you know this already.
Toe Knee in Return to Karazhan used to be bugged in that you could kill him too quickly and bug the event.
Blizzard fixed that - after I’d learnt to mitigate it, so didnt pay the fix much attention.
I’ve got both mounts from new kara, but recently got the Memory Cube quest from the Nighthold while I was doing Balance of Power - because revisiting old content is what I do in the weeks leading up to a new expac, once I’ve exhausted the pre-patch event.
Anyway, back to the story - killing Tony Knee too slowly now has him bug out and become invulnerable.
This really does highlight the lack of full circle thought in the development team, that they can introduce a bug when fixing a previous problem that is almost guaranteed to occur in the method players had learnt to mitigate the original bug.
It actually beggars belief that this can happen.