Good, super interesting, but slightly sensationalized and had some minor factual errors. For instance, the narrator refers to archaeologist looking into the documentaries subject matter as "renegades", yet this field has actually been an active area of research for some time now.
The documentary also states at the beginning that the ice age started around 2.5 million years ago and ended 12,000 years ago. This is partially correct. We are still in an ice age that began 2.5 million years ago. However, this ice age has seen short inter-glacial periods and long glacial periods. Currently, we're in an inter-glacial period within the longer ice age (unless human-caused climate change alters this). This language implies a continuous 2.5 million-year glacial period, which is wrong. This inaccuracy also detracts from an interesting and likely hypothesis presented later in the documentary. A simple 1 to 2 minute explanation on glacial-interglacial periods would have cleared this up pretty easily.
The narrator also kept stating that the the initial findings from a cave in Mexico were 30,000 years old, when the primary researcher clearly stated a Carbon date of 27,500 years plus-minus 2,500 years (this technically means a date of 25,000 years is just as likely as 30,000 years). This was kind of excessive and detracted from the science.
I place these errors and shortcomings on the production team, certainly not the scientist or science featured in the documentary. PBS NOVA has also covered many of these discoveries. I'd recommend viewers watch those documentaries too so they can get a further informed perspective.
