The Haut du Mont trial began on 7 September and jurors are expected to retire next week.

An Island Energy supervisor charged with unlawfully killing ten victims of the Haut du Mont explosion worked with “complete disregard” for health and safety, skipped management meetings and prioritised “getting the job done”, jurors were told yesterday.

Neil Armstrong (58) is charged, alongside his former Island Energy colleagues John Wright (60) and Lee Ward (59), with ten counts of gross-negligence manslaughter – one for each of the people who died following the Haut du Mont explosion on 10 December 2022.

Jersey Gas, which trades as Island Energy, also denies two alleged breaches of the Health and Safety at Work (Jersey) Law 1989.

Mr Armstrong was in charge of a network operations team consisting of his two co-defendants accused of working “exceptionally badly” to cause the fatal blast.

Jurors at the Royal Court previously heard that the three men had cut the “wrong pipe” while attempting to “decommission” gas supply to Haut du Mont – causing the St Helier Yacht Club to lose their gas supply – which led to the team reconnecting the gas pipe they had cut.

After reintroducing gas to the Yacht Club – and, by extension, the Haut du Mont flats – Mr Armstrong allegedly left an “emergency control valve” open and unplugged.

Jurors were told that the open valve “could have been identified” if the three defendants “had carried out a crucial, basic and fundamental test before restoring gas”.

James Johnstone, Island Energy’s safety and compliance manager at the time of the explosion, said yesterday in his evidence that supervisor Mr Armstrong operated with “complete disregard” for health and safety principles.

Advocate Mark Boothman, representing Mr Wright, put to the witness that Mr Armstrong “didn’t take health and safety seriously, did he?”

“I would say it was more like he didn’t fully commit to all of it,” Mr Johnstone said. “It wasn’t at the very top of his priority list.”

The lawyer continued: “When you spoke to the police in March 2023, you said he had a complete disregard for health and safety and doesn’t turn up at management meetings?”

“Yes, that’s true, he does have a disregard in certain aspects,” the witness said. “But saying he doesn’t turn up for management meetings doesn’t mean that he didn’t turn up for any of them.”

He added: “Complete disregard of health and safety – those were my exact words? That doesn’t mean he had a complete disregard for every single aspect of health and safety.

“His priorities were more towards getting the job done, than the safety considerations that go with it.”

Mr Johnstone added that Mr Armstrong embodied a “get it done” work ethic when it came to the jobs he was assigned.

“He was, in your own words to the police, a complete maverick in relation to health and safety – he was a complete maverick, wasn’t he?”, Advocate Boothman asked.

“Yes, he was a maverick”, Mr Johnstone accepted.

The defence lawyer then put to the former safety and compliance manager: “You now must regret, given your position within health and safety, that you didn’t do more to try and tackle this situation with Mr Armstrong and his team?”

But the witness countered that the responsibility for managing the team lay with senior manager James Cherry, and not him.

Commissioner Andrew Oldland, presiding, interjected to ask Mr Johnstone if he had done “anything’ to address Mr Armstrong’s reputation as a “complete maverick” who would always “be allowed to get away with it?”.

Mr Johnstone said he acceded to the then-head of regulation and risk Clive Doyle for managing how Mr Armstrong went about his work.

The witness cited an incident that took place “about a month, or six weeks maximum” before the Haut du Mont explosion which involved Mr Armstrong injuring himself during a job.

“In my opinion what happened was careless, and I went to speak to Clive about it as my line manager and head of safety. His response was: ‘You know what Neil is like, he goes at everything with gusto’.”

Jurors also heard Advocate Boothman ask Mr Johnstone whether he thought Mr Armstrong had instilled a negative working culture within the network operations team.

The former Island Energy employee replied that he had heard “murmurings” and “moaning” about Mr Armstrong and his team, but noted that “some of it can be hearsay” and “some of it can be banter”.

“How much of it is warranted, unless you are involved with it on a day-to-day basis, you are not really going to know for sure”, Mr Johnstone explained.

“Mr Armstrong is from Glasgow, as am I, and I’m very aware how gruff the Glaswegian accent can be, and at times I come across as aggressive.

“There could be a case where anyone who isn’t used to the accent can feel it is coming across as aggressive, which can imply bullying.”

Advocate Boothman put to the witness that he had described Mr Armstrong as “very intimidating” and “a bit of a bully” during interviews with the police.

“You must accept from a health and safety perspective, that somebody who has attributes like those that I’ve just read to you, is problematic from a health and safety perspective?”, Mr Boothman asked.

“Not necessarily from a health and safety perspective, [but] it could be problematic from a work relationship perspective”, Mr Johnstone answered.