I never really noticed the issue until I read this thread.
We go from Kurn being drunk and passed out, to Kurn being on the operating table and Julian asking Worf if he's sure if he wants to go through with the procedure.
Bashir doesn't argue that he can't do it without permission from Kurn himself, (which I think someone like Bashir would have), he just agrees to do the whole thing.
Worf doesn't have the rank to go to the C.M.O and order him to wipe someone else's memory.
It creates a messy situation because Worf could have just asked Kurn to let his memory be erased to get a new life, but in all likelihood Kurn would be offended by the whole thing.
So that means it was done without his consent, because they knew he would never agree to it.
OTOH, I supposed if he were in Worf's custody, it would be easier to push it through. I mean, the guy was
suicidal. But geeez..
One lesson here--if you're drunk and depressed, don't ever do it in front of Worf, lol.