That is very odd. In the commercial preview, Nick says: "It's On" and then smiles while they're in line at the airport, so that must mean that they have not yet made a mistake/fallen behind yet . And also, in the episode preview, Nick said: "No competitors left in the game, just a bunch of pansies." and we can see he's inside a cab and it's daylight outside (seems like afternoon or noon), so they couldn't of gotten lost before the airport? That must mean they got a bad flight again and fallen behind (since Rachel and TK could not possibly have beaten them to the airport)? Or that they had trouble getting directions to the train station?
Although... They might not be thattt far behind... It might be close to dusk when Ron and Chris did the roadblock.
And how do we know that Rachel is doing the roadblock while it's daytime? Isn't the picture in yellow? Maybe the editors purposely did that in the preview so that we couldn't know what time it was. Or am I missing something again...?