In the scene where Dodds (Warren Donnelly) enters the outside container, you can see "Del Boy" graffitied onto the wall. Clearly a BBC nod to Only Fools and Horses (1981) however this was subsequently set 8 years prior to the UK knowing who Del Boy existed.
Gene Hunt bets Sam Tyler "a tenner" (10 British pounds sterling) that he can solve a murder first. In 1973, 10 British pounds had the purchasing power of $72.80 in 2006, when the series first aired, so it's a quite substantial wager.