SilsoeSid
the rotor speed would need to be in the region of 1800rpm for a highish quality 30fps video speed.
The craft appears to have 5 blades. This means that the rotor speed can be 1800/5 = 360 RPM.
OK it's time to get serious.
The video was a training film for interrogators, when the Russians were fighting in Afghanistan.
A person's rate of blinking increases when nervous. The interrogators would start by making the captive very nervous. When the prisoner said that the rotors on the overhead helicopter had stopped turning the interrogators knew that it was time to start the questioning.