Retroactive Recognition: One of Pierce Brosnan's first film roles was in The Long Good Friday, pretty much as a walk-on. Back when it was made, Brosnan was an absolute nobody. By the time the DVD came out (twenty years later), he had his own segment on the special features, talking about how he got the part.
Technology Marches On: Harold's line "You'd need a million dollar COMPUTER to understand this!" somehow sounds unintentionally funny now (as if he thinks computers can do anything). Also it conjures up humorous mental images of big clunky computers from this era.