[JesseK]

<R65>, in the wording of the first paragraph, stipulates that all pneumatic parts must be COTS and unmodified except for assembly. Combined with <R70>, you get the working psi of all COTS pneumatics shall not exceed 60psi. It's a bit of a stretch, but <R74> also says something about "Commanded Motions" going through one valve.

Without further details providing evidence that the cyllinder would not absorb more than 60psi worth of force AND that the cyllinder would not intentionally absorb shock due to another mechanism's actuation, the three rules combine to make a COTS cyllinder-based shock absorber illegal.

I agree, that answer is somewhat unclear, but perhaps these three rules are the basis of the ruling? I do not necessarily agree with the GDC's justification of their ruling since it's a quite a stretch as it's worded. The underlying issue from their perspective is probably safety and without many more details on the design they probably wanted to error on the side of safety, thus finding some nuance words to justify it. I personally would not want a 125-psi rated shock absorber absorbing the impact of some poorly-designed robotics subsystem anywhere near someone who wasn't behind a safety wall.