Pond, from the way people have described the events in the video, the officers were slightly surprised by the initial approach of the subject. They may not have felt he was "contained" in those circumstances.
A really good example of containment working, and LTL means subduing a deadly weapon armed man, was the video shot in Seattle several years ago. A man was acting odd on a downtown street, menacing people with a katana.
Seattle police were able to contain him, but there were several officers on the scene, and the guy had his back to a wall. The officers kept him at an impasse, until a Seattle fire truck was able to come into play, and a water cannon disarmed the guy and knocked him flat.
There are major differences, though.
In the Seattle case, there were a lot more officers; the suspect never made a convincing, threatening move toward the officers (I'll tell you right now that if somebody advances on me with a katana, and I think he's serious, the gun is no longer the last option); the suspect was effectively contained, so there were no concerns about bystanders; and the availability of the fire truck was the clincher.
You seem to be worrying about "eight seconds." On the one hand, it's not a lot of time. On the other hand, it's plenty of time for somebody to harm or kill another.
I have an acquaintance who was involved in a hot refueling accident with an A-6 on a carrier. He was seriously burned, but managed to get out of the plane. Crash crew ran into the fire and pulled him away from the aircraft.
He saw the flight deck video recording later, and realized he'd only been on fire for thirteen seconds. He says that was the longest thirteen seconds of his life.