I'd noticed the same thing...
I took this to be an error, and though I haven't actually prepped these parts, I'm not far from working on these parts. My final decision on which way to go hasn't been made, i.e. whether to use CS4-3 or LP4-3 rivets. Might pay to check how tight of a fit the rear baggage bulkhead is, as it might need a fully flush surface to allow installation / removal.
RV-9, Empennage and Wings about done, Fuselage started.