Ah. Math.
If you think only about the math and not at all about the practicalities of ski racing, this is a gotcha.
This spec mandates not only the jitter rate of the beam, it also mandates the diameter of the beam.
In the first example, that 8mm object (about the size of two pencils) represents a ski pole. That part of the spec isn't about jitter rate, it's about requiring a beam wide enough so that a ski pole will not totally obscure the receiver to the point where the cell generates an impulse.
The second example is about capturing an impulse from a racer's shin (100mm = about 4 inches) at a speed well beyond that which an alpine racer will go.
In abstract terms, a beam the diameter of a human hair would flunk this spec because it could be tripped by a ski pole. Obversely, a beam the diameter of a trash can lid would also flunk because a racer's shin wouldn't cause an impulse.