Such a shame about the rain.
I think what PP is alluding to was the traffic chaos around Manchester, especially the city centre and Etihad on the night of the concert.
There were a number of additional factors though to all of the concert related traffic, with problems on the tram lines with a car on the track on the line to the Etihad, a crash between a tram and bus in the city centre etc... It was traffic gridlock around the city centre/Etihad and surrounds apparently.
I'm guessing this was a knock on to PP's taxi not turning up and his being late for his exam.