And don't get me wrong, I've got no problem pointing out a more experienced opponents' mistakes, or what I would have done with their list, after the game.
AtomicPFryingPan summed up the point I was trying to make at the end with saying the definition of sportsmanship: don't be a jerk. Whether pointing out a mistake or letting your opponent make it (again, both of those things I'd consider in context), don't be a jerk about it, shake hands after the game, if there's time to discuss anything you want to point out after the game, then do so as long as you're not a jerk about it.