after Paul had been fired and was heading for the lift to go and get into the Taxi, he was wearing a very unpleasant pair of tan coloured "kipper feet" shoes 
and then, when he was walking to the said Taxi, clutching his suitcase, he was then wearing a pair of ordinary black shoes
I can't believe that he would have had time, as the Brentwood House lift was plummeting down and the tinny lift voice- ver person was saying "GROUND FLOOR - EXIT, YOUR TIME IN THE APPRENTICE IS OVER - GOINGGGGG DOWWWWWWWWWWWWWN", to have opened his case, rummaged around (discarding his everso handy jelly pot and tin can for sausage cooking
) to find another pair of shoes 
I want to know how he did it

and then, when he was walking to the said Taxi, clutching his suitcase, he was then wearing a pair of ordinary black shoes

I can't believe that he would have had time, as the Brentwood House lift was plummeting down and the tinny lift voice- ver person was saying "GROUND FLOOR - EXIT, YOUR TIME IN THE APPRENTICE IS OVER - GOINGGGGG DOWWWWWWWWWWWWWN", to have opened his case, rummaged around (discarding his everso handy jelly pot and tin can for sausage cooking
) to find another pair of shoes 
I want to know how he did it