Documentaries these days are more about the visuals, the cool movie stars and "extreme" experiences but no much science. I learned more from reading the first paragraphs about stress on Wikipedia. That said, this documentary is way better than the Will Smith's one.
A stress training, or any "training" whatsoever, takes more than a couple of days to get incorporated into one's mind and body. And because of that, I think this chapter is a bit misleading. People want everything right away, but that's not how psychology and permanent change works. The techniques shown in the show are accurate and effective, but not in such a short time. At that stage, they are just tricks that may work or not in real situations.
Also, the stress response is a normal and necessary response in situations such as walking down a crane 200+ meters high. It's a survival response! And it's not only measured by beats per minute.