They did the way more expensive version briefly mentioned towards the start of the video, having 12+ cameras with ridiculously fast shutters (as low as 10 nanoseconds) arranged to run in seqeunce.
That was probably not the more expensive version in that case.
Why?
Because of the cost of making and detonating so many bombs.
Scanning a single pixel over an image? How does that work with an explosion? The laser pointer is reproducible
But that bears no relation to what happened in the video.
The rapatronic camera had an incredibly fast electronic shutter. To record a video they needed one camera per frame. Rather like "bullet time" in the movies. The technique in the youtube video is completely different.
It's not completely different. I'd argue it's the exact opposite. Instead of using a single single-pixel camera to record video of a repeatable event, a sequence of regular film cameras captured photographs of an unrepeatable event.