As much as I was rooting for Rob and Amber, I don't think it was fixed.
Aren't there stiff penalites for rigging a contest? Particularly using public airwaves? (After the Quiz Show Scandals). When I worked at a Boston radio station we were very very careful to make sure our contests were impartial.
If it ever got out (from the Pilot, or Gate Agent) that the Race was rigged, who would ever watch the show again? And those lucrative deals with Travelocity and other in-game sponsors would be gone. Travelocity could also sue (you associated our product with a dishonest hoax tarnishing our image).
We should also remember, with a film crew taping, gate agents may be more accomodating and helpful than normal.
I do think that in planning the next Race the producers need to put together a better last leg. Can you imagine how dull the last 40 minutes would have been if Rob and Amber made it to Miami alone??? They should have had one or two more steps in Miami to make the race close in case one team arrived in Miami two hours earlier.
U&J (again, glad they won) also lucked out with their cabbie. It appeared his native language was Spanish, so when he asked someone "Where is the King of Havannah's?" he literally asked "Donde esta el Rey de las Havannahs?" By asking in his own language, he inadvertantly asked for the exact name of the shop! It would have been stronger to make teams get dropped off at an intesection with a clue box, make them find the place on foot.
All in all, a great race overall.