The bulk of the time spent changing a tube is inspecting the tire for the source of puncture. Sometimes the tire takes some wrangling to get back on to the rim. And let's not forget pumping up the tires with my mini-pump if I'm on the road takes a minute or so. If the tire went back on easily and I did a quick cursory check of the inside like he did, and didn't have to pump up the tire I could do it in under two minutes.