Maybe this is just a raid thing, but I run Tempest Spine a lot and it seem that many people claim to know the way up the mountain when really they dont know jack.
Twice in the last week we had re-entries because someone didnt know the way up and didnt ask for help. I think it would be nice if a confirmation box popped up say "PlayerX would like to re-enter this quest". I have run quests where it has been necessary and the XP hit was acceptable.
20% loss i think. Ouch. 11 other people really mad. Too far in to restart.