The "Quan Thang massacre" sequence was a nine-minute-long one-shot.
Although the Quan-Thang sequence is a 9.5 minute long-take, it wasn't all shot at once. According to director Greg Yaitanes, the first 7.5 minutes are an uninterrupted complete take. Then they cut twice, not because they couldn't do it, but for safety reasons. The first time comes when the plane flies over the sky. After that there is a big napalm explosion, and they had to be vigilant about it, for the safety of the cast and crew on set. The second time is when a grenade is thrown, and they had to light some people on fire.
In the beginning of the episode, in the Vietnam flashback, there's a boat with the phrase "HORLA" written on it. "Horla", was the title of episode 5, before a scene was cut and they changed it to "Coffee Blues". The scene that was cut from episode 5, is the first scene of this episode.
"Nuoc Chay Da Mon" is a Vietnamese proverb which roughly translates to "water smooths stone" or "water erodes stone".
Peter Mullan (The Broker) & Josh Randall (Detective Tommy Olsen) also worked together on Ozark (2017) as Jacob Snell & Bruce Liddell respectively.