Does "one aside" here mean "I, as a participant, ..." or "apart from this, ..."?
Later, tumbling down the main steps of Tate Britain as we head first for Lambeth Bridge, the city is awash with the wail of sirens and clacking of helicopter rotor blades.A state of emergency. Chaos, disruption and, above all, noise accompany us all the way. The artist can barely make himself heard at times. One aside I manage to catch as we set off: ‘everything you see and hear in the city is the consequence of a decision. Cities are made by humans, every bit’.