I think the show's editing has gotten predictable because it's quite obvious that Nat & Kat won.
From what I remember, they're the only final 3 team to get relevant face-time on every episode. Jill & Thomas and Brooke & Claire were each non-existent for at least one episode.
At every possible opportunity, the editors emphasized Nat & Kat being in jeopardy. Whether it was the sunglasses selling roadblock, the taxi-driver who wouldn't change direction before the commercial break in Ghana, or getting lost in Oman, it's the same thing that the editors did to Nick & Starr, Tammy & Victor, and Dan & Jordan.
I still remember when they were helping out the school in Ghana, Nat & Kat were one of two or three teams, and the only final 3 team, to talk directly to the camera while they were helping out.
From the editing, it's a no-brainer that Nat & Kat won.