Well, it's clear to me that he thinks the law should apply, but only when it favors and is convenient to him, lol. The clause is claiming that the contract rules over law, and that the law only applies if the contract doesn't already address it.

FYI to anyone who ever finds something similar in their own contracts, contracts absolutely CANNOT override law. Any terms and conditions that contradict the law, including those which claim to override the law, are treated as null and void, even if you signed it. Certain rights are protected, you can't just sign them away. Contracts can add to them, not take them away. Law always trumps contracts, never the other way around.

Right. This clause contains 2 sentences that directly contradict one another.
The first sentence is 100% correct.
The second is 100% incorrect: contract clauses do not and cannot over-rule Korean Labour Law.

Or the law of any country as Chinguetti said above.

It's frustrating because the boss is as stubborn as anyone I have ever met. He's one of those types of people that believes there are only two opinions on this planet: his and people who are wrong.

I am not in need of it now. It's just an easy point of contention. I know how to play the people game.