You have now angered the tire gods... expect a string of flats as punishment!

I'm lucky enough to have a tram line which runs 85% of the length of my commute, along with two easily accessible LBS and a third within 10 minutes walking distance of the tram route, so in the three times I've had flats, I jumped on tram to the nearest LBS and had the tube swapped out with a new one within minutes, so I've never been late concerning flats.

Unfortunately I did have problems with broken spokes before I changed to good quality wheels which delayed my arrival to work substantially.