The defence lawyer for former locomotive engineer Tom Harding says the implementation of one-person train crews at Montreal, Maine and Atlantic (MMA) railway, combined with substandard safety practices, were the conditions that led to a perfect storm — culminating in the 2013 Lac-Mégantic tragedy.

Charles Shearson wrapped up two days of closing arguments at the Sherbrooke courthouse Tuesday, rejecting key testimony from Crown witness Randy Stahl, the MMA manager in charge of locomotive maintenance.

Stahl, the only American company official called to testify by the Crown, told the court there was no difference in safety between trains operated by one person or two.

"If it doesn't make a difference," asked Shearson, "why did Quebec North Shore & Labrador (QNSL) railway impose 69 conditions when they implemented a one-man crew?"

"Why did they make engineers go through 10 days of training, and why did they make it mandatory for engineers to use [extra safety devices]?" he asked.

The Crown's expert witness, Stephen Callaghan, testified 69 conditions had to be filled before one-man crews were given the green light to operate at the Quebec North Shore and Labrador (QNSL) railway, where he used to work. (Alison Brunette/CBC)

Shearson pointed out the Crown's expert witness, Stephen Callaghan, testified QSNL was at the apex of railway safety at the time.

He said QNSL also ensured locomotive engineers working alone were closely monitored, which wasn't the case at MMA.

Shearson's client is one of three former MMA employees charged with criminal negligence causing 47 deaths in connection with the derailment and ensuing explosions in downtown Lac-Mégantic.

Also charged are former operations manager Jean Demaître and ex-rail traffic controller Richard Labrie.

Harding, Labrie and Demaître all waived their right to present a formal defence and did not testify.

Locomotive 5017 was the defective lead locomotive on the runaway train the night it derailed in downtown Lac-Mégantic. The ensuing explosions killed 47 people. (Richard Marchi/RRPictureArchives.net)

Transport Canada axed one-man crews after disaster

Earlier in the trial, the court heard that before the disaster, Transport Canada changed its rules, so that MMA did not need permission to operate single-person crews — a practice it implemented not long before the disaster.

The only condition imposed on MMA was to add a mirror to the driver side of the locomotive.

"After the tragedy, single-man crews were not allowed anymore," Shearson reminded the jury.

"If it doesn't make a difference [in safety] why take it away?"

Shearson asked jurors to recall an audio recording of a phone conversation of Harding calling into the Farnham train station hours before his ill-fated last trip, in which he'd asked the rail traffic controller on duty if he'd be working with a conductor that day.

The answer was no.

"Perhaps if he had been, it could have prevented the accident," said Shearson.

Harding was 'on the ball'

Shearson asked jurors to consider Harding's reputation and recalled the testimony of several of his former MMA colleagues at MMA.

Throughout the trial, many of them painted Harding as patient, helpful, and professional.

Crown witness Yves Gendreau, a former MMA train inspector who'd worked with the accused, told the court he'd been impressed by Harding, describing how the train engineer had opened the window of the locomotive when testing his brakes to hear that the cars were moving properly.

Shearson gave jurors several other examples which he said showed Harding was safety-conscious and on the ball.

"Five minutes after perceiving a problem with the locomotive, he called Farnham to say the locomotive was not 100 per cent," Shearson told jurors, referring to an audio recording jurors heard earlier in the trial.

Shearson also replayed a conversation Harding had with American rail traffic controller Dave Wiley when he arrived in Nantes with the train on July 5, 2013.

Accused locomotive engineer Thomas Harding, left, speaks with defence lawyers Charles Shearson, centre, and Tom Walsh, right. (CBC/Alison Brunette)

In the recording, Harding describes problems he'd had with the locomotive in detail, to which Wiley responds, "We'll check it out in the morning. That's all we can do."

Near the end of his closing statement, Shearson recalled the testimony of ex-MMA employees Michael Horan and Jean-Noël Busque, who both told the court that on the night of the tragedy Harding donned firefighter gear and risked his life to help haul away fuel cars which hadn't derailed.

"Does that demonstrate someone who has a reckless state of mind, someone who is careless?" Shearson asked.

"We can't hold people criminally responsible for not being perfect."

Shearson told jurors Harding's conduct was reasonable when put in the proper context.

"That context was, there was no specific training for Nantes, and people were not forewarned about the risk," he said.

Number of handbrakes not a standard

Throughout the trial the Crown has faulted Harding for not applying enough handbrakes to the train left idling overnight in Nantes, and for not conducting a brake efficiency test to check if those handbrakes could hold the train.

Earlier in the trial, the jury heard that Harding had applied seven handbrakes to the train, as well as the locomotive's independent airbrake.

Shearson argued none of the MMA locomotive engineers or train conductors who testified knew exactly how many handbrakes were required to secure a fuel train in Nantes.

During cross-examination, Shearson had asked those witnesses how many handbrakes they routinely applied to trains.

Several of them answered that a chart did exist indicating how many handbrakes to apply but said they generally used a formula: 10 per cent of the number of train cars plus two, which indicates the minimum number required.

Callaghan, the Crown's expert witness testified that at Nantes, that minimum number wouldn't have been enough.

"Why is it normal that no one shared the information that on a train past a certain weight in Nantes, there would have to be more handbrakes applied?" asked Shearson, wrapping up his closing arguments.

Superior Court Justice Gaétan Dumas is expected to instruct the 14-member jury Wednesday, before jurors are sequestered to deliberate.