This is about Water 7.
We all know that CP9 are agents of the World Government, and the villians of this arc. However, Oda told us that before we even landed on W7.
Chapter 323. (From Stephen's site)
Nami: Here we go, then!
Thanks for all the info, Cocoro and Chimney!!
Luffy: Prepare to sail, boys!!
Chimney: Take care!!
Cocoro: Look out fer them government officials!!
Don't you just love that? It pays to reread.
Has anybody else found other examples such as this?