Counter Question - If their code works, why would they post for review ? Normally, the post I see of code is because it does not work. When my code works, I am happy, and I press on.
Umm.. because sometimes you want to know how you could improve your design and generally write more elegant code? Going at it with the mindset that "if it compiles, it works" is a surefire way to get yourself in a productivity black hole once your code becomes impossible to maintain (and too expensive to refactor) as a result of brainless code-monkeying.
Code review does not mean "this does not work, fix it", it means "so I've done this, but this method here looks kind of awkward, how can I improve my interface to expose the minimum functionality possible while keeping it flexible, I need to query the database twice here, how could I refactor to require only one lookup, etc..", that kind of stuff.