Quote Originally Posted by Geoduck
... a guy (probably about 25) walks up and is standing about 10 feet away, with a kilt sitting w/ pleats facing forward.

Is there a tactful way to correct him? or is it best to just leave well enough alone?
I ran into this situation myself. The guy was parading around pleats-forward, and I just told him, "Dude, you've got that on backwards." He replied with complete conviction, "No, you can wear it either way."

Moral: Go ahead and correct him (he's probably very new to this, and probably want to get it right), but don't expect the correction to necessarily stick.