Guild Wars 2

Is It bugged or I have to get this last achieve that I dont have?
I have done this big event 2 times and I still dont have that one.

That escort actually consists of Laranthir and Skybreaker (or whatever his name is). If one of them (usually Skybreaker) doesn’t complete the run because he gets stuck with mobs because no player is doing that part, the event won’t complete even if you escort Laranthir succesfully.