When Will drinks the coffee the sex worker brings to him at midnight, "PRET" can be seen on the coffee-cup sleeve. However, the Pret A Manger at King's Cross closes at 8pm.
(at around 52 mins) When Will returns to the office after chasing Miro, he is met by his wife and Sandy who have been "worried sick" about his whereabouts. However, he was carrying his cell phone and they could have called him any time.