Originally Posted by
Racing Dan
Was it bad luck? Sure it was, but the amount of bad luck you are likely to experience does vary depending on the gear you choose. - Some tyres are (much) more susceptible to cuts and flats than others.
Either the tube was pinched between the bead and rim, installation error, or excessive heat from braking softened the rim or bead allowing the tube to slip out, rider error. Luck had nothing to do with it.