The opening post was about a psychological effect to which this poster responded "No. I wrote up the computations explaining why." and linked to a paper which had as a conclusion an increase in breathing rates.

My point is that a crowded room likely has more than one causes which could explain why productivity is lowered and decisions making worsened.

You won't notice an autonomic response but your brain likely will and it might very well answer by releasing adrenaline, cortisol, etc., and make you more anxious and stressed to encourage you to leave the environment that is causing the increased breathing rates.