I didn't watch it. Did it cover the million (mostly Catholic and Evangelical converts) who were massacred between 1947 and 1954 in N Vietnam?
No mention of a massacre that I recall but it did cover the large number of Catholics & Buddhists who left the North in that time.
From Wikipedia:
In the early 1950s, the Communist government in North Vietnam launched a land reform program, which, according to Steven Rosefielde, was “aimed at exterminating class enemies.” Victims were chosen in an arbitrary manner, following a quota of four to five percent. Torture was used on a wide scale, so much so that by 1954 Ho Chi Minh became concerned, and had it banned. It is estimated that some 50,000 to 172,000 people perished in the campaigns against wealthy farmers and landowners. Rosefielde discusses much higher estimates that range from 200,000 to 900,000, which includes summary executions of National People’s Party members.