I watched the documentary. It was interesting.
I am a bit skeptical about the first parts and the "debate"over the origin of tea. I don't think there has been a raging controversy over the exact origin of Camellia sinensis, southern China is clearly the center of diversity. The evidence the film producers provided did not seem very scientific. They referenced several legends about tea from Southern China as direct evidence. I certainly believe this material is valuable in the story of tea but is not acceptable proof to the natural distribution of the plant. The fossil they mention "magnoliid" they dated in the cretaceous. Tea is not even in that lineage (it is an asterid). This level of taxonomy is not particularly useful in floristics since these lineages are pretty much globally distributed. Besides these matters are typically discussed using floristic provinces as geographic unit rather than politcal boundaries.
(Biogeography rant ends. Can't help it sometimes
The second part about the history of pu erh was good. I did especially enjoy the cosmic temple of aging cakes!