The brief of the mission had been to arrest three IRA members who were suspected by the Joint Intelligence Committee of being in the process of organising a bomb attack on the changing of the guard in Gibraltar, before such an attack could take place. The SAS were authorised the use of deadly force 'if those using them had reasonable grounds for believing an act was being committed, or about to be committed, which would endanger life or lives and if there was no other way of preventing that, other than the use of firearms'.
The SAS had claimed that McCann had made an 'aggressive move' towards a bag he was carrying. They had presumed he was intending to trigger a car bomb using a remote control device.After McCann was killed, Farrell made a move towards her handbag and was therefore killed on similar grounds. Faced with arrest, Savage moved his hand to his pocket; the SAS therefore killed him. In all, McCann was shot five times, Farrell eight times, and Savage between 16 and 18 times. All three were subsequently found to be unarmed. Ingredients for a bomb, including 100 pounds of Semtex, were later found in a car in Spain, identified by keys found in Farrell's handbag.
The documentary interviewed witnesses who claimed that the SAS had given no warning prior to shooting, and that the event had been carried out 'in cold blood'. In addition, the defence that the IRA team may have had the capacity to trigger a car bomb by remote control, was subject to criticism, including that of an Army bomb disposal expert.
The New York Times (June 13, 1989) review stated: "Events leading up to the Gibraltar killings are depicted in a reconstruction made for a British television documentary. Questions abound. Was the I.R.A. trio, carefully followed for days, in fact lured into Gibraltar? Why did the police fail to photograph the bodies or gather forensic evidence? Why was the press - Britain's tabloids were jubilant - told lies about a huge car bomb being defused and about the three suspects having died in a gunfight? This documentary's understated observation: There was a strong air of Government cover-up and disinformation.
The then Foreign Secretary, Geoffrey Howe, attempted to prevent the broadcast of the programme in the United Kingdom, claiming it would prejudice the official inquest into the event. The Independent Broadcasting Authority refused, stating: 'the issues as we see them relate to free speech and free inquiry which underpin individual liberty in a democracy'. Following transmission, the programme was heavily criticised by sections of the press, notably the Rupert Murdoch-owned papers The Sunday Times and The Sun. The then Prime Minister, Margaret Thatcher, was said to be outraged by the documentary, and was increasingly concerned about ITV's 'monopoly' in independent broadcasting. Mrs. Thatcher said, in an interview: 'If you ever get trial by television...that day, freedom dies.' It was not shown in Gibraltar where the inquiry was held.
Carmen Proetta, an independent witness told Thames television, ‘They [security forces] didn’t do anything ... they just went and shot these people. That’s all. They didn’t say anything, they didn’t scream, they didn’t shout, they didn’t do anything. These people were turning their heads back to see what was happening and when they saw these men had guns in their hands they put their hands up. It looked like the man was protecting the girl because he stood in front of her, but there was no chance. I mean they went to the floor immediately, they dropped.’
The researcher for Thames Television which made the programme Death on the Rock believed Ms Proetta’s evidence as it coincided with another account they had received.
A 1989 inquiry into the programme headed by former television management executive and government minister Lord Windlesham largely cleared it of any impropriety, although it found some errors had been made.