Yes and No
They will of course say it is and it can be, however not as they are showing it. So what is it then, the way they present it is the same as we are presenting Kyusho, in a fully incapacitating affect, without the side affects (like killing someone) and especially when they do the correct revival.
The first knockout by this group, occurred in a Chinese restaurant. This film clip was sent to me by a friend in Switzerland and he was asking questions about the the effects and I concurred with his speculation. What you see happening is the young kid in the Chinese restaurant and one of the "Dim Mak" guys tags him on a "Dim Mak" target. We see the immediate as well as the prolonged affects taking place as they did not revive him right away. We also see the revival taking considerable time as the were using the incorrect ones, until the instructor stepped in and instantly revived him.
This will most likely be seen by most as a technical knockout, or a standing knockout, but the only reason he was standing was there were several men supporting him and trying to revive him. however their revivals were high and on the wrong side of the body. This is why the kid didn't pick back up quickly and again why we train people in revivals incessantly, because you have to know what to do instinctively. It would have saved this kid a minute minute of discomfort and trouble. As is typical in this type of strike, it looks like he stopped breathing as well as experiencing a Vasovagal Syncope or fainting episode. His pupils were fully dilated about the size of his entire eye, so there were many other difficulties, as well.
This target has been used in many "Dim Mak" demonstrations from Asia over the years and you will see them in the film. Pay close attention to the 3D Anatomical section as well, to more fully understand the physiological processes and anatomical structures involved.