The manslaughter prosecution against David Duckenfield, the former South Yorkshire police officer in command at Hillsborough when 96 people were killed in a crush, is “unfair”, his barrister has argued.

Ben Myers QC, setting out the issues on which he will base Duckenfield’s defence, said he was being “singled out unfairly”, that many other people made mistakes, and other factors contributed to the disaster – including the behaviour of some Liverpool football club supporters.

“By virtue of bad stadium design, bad planning and some aspects of crowd behaviour, some aspects of police behaviour, mistakes by various individuals and genuine human error, this tragedy happened,” Myers told the 12-person jury at Preston crown court.

Duckenfield, now 74, was promoted to chief superintendent and appointed to take charge of the FA Cup semi-final between Liverpool and Nottingham Forest just 19 days before the match took place on 15 April 1989. He had “limited experience of Hillsborough, and none as a match commander”, Myers said. He told the jury that Duckenfield’s case is that “he wasn’t negligent and did his best in extraordinary circumstances”.

Myers questioned whether the risk of death by crushing in the central “pens” of the Leppings Lane terraces, which the prosecution has described as “obvious and ever present”, was foreseeable. He said: “Where the tragedy at Hillsborough is concerned, a lot of people have been very wise after the event.”

Myers acknowledged that it is “terrible” to think of the crush that caused the deaths and said his questions on behalf of Duckenfield were not asked out of “lack of sympathy with those who have suffered”.

He said: “In no way do we seek to insult Liverpool football club or its supporters, or the city of Liverpool itself. And I would be grateful if you, and everybody listening, would remember that.”

Myers said hooliganism at football matches was the context for the disaster 30 years ago, explaining why there were high metal fences at the front of the Leppings Lane terraces, and the style of policing: “So we say, let’s not try to rewrite history: some of the crowd behaviour would horrify many people at a football match today.”

Referring to the policing of the time, which was aimed to contain hooliganism, Myers said: “I’m not suggesting the conduct at this match was at that level but it was the background to it.”

Myers set out the basis of Duckenfield’s defence after Richard Matthews QC concluded his opening of the prosecution’s case on the third day of the trial. The jury was shown colour photographs of the crush, which a survivor described as “a scene of horror”. Colin Moneypenny, a survivor in pen three, Matthews said, would give evidence that he could not move because of the “intense pressure” around him and he could feel a body underneath one of his feet.

Matthews said Duckenfield was accused of an “extraordinarily bad” series of failings at Hillsborough, where the risk of death by crushing, if the crowd in the pens became seriously overcrowded, was “obvious and serious”.

These alleged failures included Duckenfield lacking detailed knowledge of the ground and how Liverpool supporters would be admitted through the 23 Leppings Lane turnstiles, a failure to monitor the numbers of people building up outside the “bottleneck” at the turnstiles, and to take any action, including delaying the 3pm kick off, to relieve that build-up.

Duckenfield ultimately ordered the large exit gate C to be opened to relieve the overcrowding at the turnstiles, after being warned that somebody could die outside. When he did so, Matthews said, Duckenfield gave no thought to where the incoming supporters, calculated by an expert to have been 2,603, would go. It was “inevitable”, Matthews said, that the supporters would go through a tunnel facing them, which led to the central pens that were “already packed”.

“Ultimately it will be a matter for you to decide,” Matthews told the jury. “But the prosecution allege that the evidence you will hear and see will demonstrate to you that these failings went beyond error or even serious error; they’re rightly to be viewed as extraordinarily bad – in the face of an obvious and serious risk of death.”

The criminal charge of manslaughter against Duckenfield relates only to 95 of the people who died. The 96th victim, Tony Bland, suffered critical brain damage and died four years later in 1993, when life support in hospital was lawfully withdrawn. The law in 1989 stipulated that no charges relating to a death could be brought if the victim died longer than a year and a day after the alleged criminal acts.

Duckenfield and Graham Mackrell, the former Sheffield Wednesday secretary and safety officer who is accused of criminal breaches of safety legislation, have already pleaded not guilty in pre-trial hearings.

The trial continues.