They occupied it, but did not annex it or make it their permanent territory. Hence my suggestion above, to distinguish "occupying" (which means the territory will be returned at the end of the war and no penalty if the war is "just") vs permanently "annexing" (which should be penalized). For example, if the US made West Germany its 51th state, they should get warmonger penalty for that even if Germany DoWed first.
So, you're saying Napoleon surely would have, should have, received a warmonger penalty. Ok you got me. Have a nice day.