They always like to exaggerate the tech a bit. But, yes, using reflected light and running it through a frequency modulation detection can resolve various things about velocity from a target, including something like the profile of how capillaries in the skin expand and contract from the pressure of the heart. So, yes, you could tell people apart by that profile with sensitive equipment.
However, you would first need to profile them. Then, you would need to have relevant sample sizes to tell just how much variation existed among people. It's one thing to be able to tell who is whom within a platoon using it. It's another to be able to use it as a true biometric similar to a fingerprint.
The XboxOne's kinect could get pretty close. It used time of flight IR to map distance and could measure your heart rate by detecting that same expansion of the capillaries in the skin.