well, he might have been a bit touch and go with the training I guess, touching into the darkside...after all it's not like he has a Jedi temple to go to or a holocron or books to learn from and hes not visiting his trainer often enough...busy with the war an all.

He might have found it a useful and harmless tool of intimidation.

A normal jedi would most likely do the " I am not here" trick and let the pigs get back to the through.

Should anything be done to it as we now know Luke does not have all kinds a jedi info at hand. plus he is supposed to touch the fringes of the dark side ain't he?