I was there (well, observing, at least)! You also found out that it was audio-based, surely? You even mention it in the first video, as I recall. You wound up with a duvet over your hands to drown outsuppress the noise so the microphone wouldn't pick it up and trigger the detection software that would close the noise gate. Unless something's changed since then.

Append: also if it only triggers above a certain user threshold, that could just be an incentive to form smaller groups to begin with…