Be careful of watching television broadcast elsewhere first on PBS, they sometimes edit for time. I know they cut down almost every episode of Call the Midwife (about 55-58 minute originally) to make it possible to fit the intro and outro commercials so the whole package fits into their broadcast schedule and these edited versions of the show are the ones on the region 1 DVDs most recently. This documentary was broadcast as a single episode but I have not looked into any changes made.