This passed without incident because everything was stacking in the right direction making the risk very low; competent experienced belayer paying full attention and climber did not fall at that specific moment. However imagine this at the lower end of the range of competence, experience and care being taken an then multiply that by every in door route climbed in the country over several weeks and even though the probability is still low the dice is being rolled many many times. It now occurs to me that we might have unintentionally introduced an additional complication that could potentially lead to an accident in the future. This is a very recent change, only this week I noticed we are now requested to belay in a face mask. As with any change that is made to a safety critical activity this needs to be properly risk assessed.