Well I think only the person stuck may use nudge, as other wise it could be abused, say if someone is standing or sitting on a ledge overlooking hydlaa, someone sneaks up and /nudges them and whaaaaaaaaaathump..
However if someone could nudge themselves, and it would like, wiggle them around that would work.
(Just a side note, most of the time when you get stuck, press the auto run button instead of /unstick, most of the time this works and you'll be freed)