What happened to him towards the end?
Michael seems not just exhausted, but ill towards the end of the series. You notice a real difference after Colombia. At least in Cartagena he is still quite cheerful. But after that the trip seems like torture for him. He has stopped enjoying it and the filming appears rushed. The treatment of North America is skimpy compared to other regions, and then he just gives up on getting back to the starting point, even though coming full circle was the whole point.
Does anyone know what exactly happened to him? Maybe someone has read some background on the filming. Was it Montezuma's revenge, or an animal bite, or something specific like that? Or was it just the fatigue of the trip catching up with him as others have suggested on this Board?