Through his legal career, Macpherson was involved in numerous important cases, including the 1993 trial at Old Bailey acquitting three ex-detectives of lying over evidence against Patrick Armstrong, a member of the Guilford Four, and also the case that resulted in the conviction of the serial killer Robert Black in 1994. He also presided over the case which resulted in paying of damages to British journalist Kate Adie over allegations of sympathetic coverage toward Colonel Gadaffi as a part of her coverage of the 1986 United States bombing of Libya. Some of his other cases that resulted in damages payout included singer Dusty Springfield over a television sketch portraying her drunk performance, and another to British politician David Penhaligon's widow for his death in a car accident.