"I disagree. I think the KLM rules would apply since it's KLM-operated."


I agree with Channa: you are on KLM, so KLM rules apply. Look at it this way: At the completion of the flight (if/when your miles don't post correctly, you'll have to mail in your boarding pass, right? Your boarding pass will say KLM on it, since they are the operators, which means they'll issue it. The boarding pass will most likely have the fare class on it. Soooooooo, when you mail it in to the OPSC, the poor slob sitting at the desk will see a piece of paper with KLM on it, your name on it, the booking class on it. They won't have a clue that it was purchased as a NW ticket! ^