A Vancouver man accused of impaired driving causing death testified gravel road conditions and a momentary distraction are to blame for the crash that killed his co-worker.

Christopher Maxwell-Smith took the stand in his own defence Thursday.

The 27-year-old was behind the wheel of a van carrying himself and five co-workers when it crashed near Pelly Crossing on July 8, 2010, killing 27-year-old Valentino Vella, also of Vancouver.

Maxwell-Smith is on trial in territorial court facing the impaired driving charge and other related charges, including driving with a blood alcohol level over 0.08.

He testified to having had three beers with dinner between 8 and 9 p.m. before the group decided to drive from Pelly Crossing to Carmacks for groceries and beer.

Maxwell-Smith said he was "not wild” about going to Carmacks because the group, who had been doing work on the Pelly River Bridge, had to work the next morning.

Though he did not generally drive the group's Kia Sedona minivan, Maxwell-Smith told the court the others were intoxicated, so he believed it would be "most responsible” for him to drive.

He didn't feel intoxicated, he said.

Though Maxwell-Smith testified he could not remember when they left on the trip, others have testified it was around 9:45 p.m.

The 27-year-old said his friends in the van, including the deceased, were laughing and engaged in horseplay when Vella got out of his seat to reach for another passenger's iPod.

Maxwell-Smith said he turned his head for a moment. When he looked back, he saw a curve in the gravel section of the North Klondike Highway which was under construction.

What happened next "felt like a lifetime” but actually only took a split second, he said.

The van drifted onto the soft shoulder. The accused testified he tried to correct the mistake, but overcorrected and went into the oncoming lane.

It was then that the van left the road, hit a ditch and rolled, landing back on its wheels, he said.

Maxwell-Smith, who has taken many first aid courses, began performing CPR on Vella, who was discovered on the road outside the vehicle. He had not donned a seatbelt.

Maxwell-Smith testified the man did have a pulse at some points and was initially making noises when he was found.

Vella was later pronounced dead at the scene by staff from the Pelly Crossing nurses' station.

Originally, another passenger in the vehicle attempted to take the blame for driving the van, but Maxwell-Smith testified he never asked his friend to do that.

Under cross-examination by prosecutor Eric Marcoux, Maxwell-Smith insisted he was only going about 105 km/h at the time of the crash.

The speed limit in the construction zone was 70 km/h.

A crash reconstruction expert testified earlier in the week-long trial that the van was going 101 km/h when it left the road but was likely travelling faster before it swerved.

Marcoux pointed to a statement Maxwell-Smith gave the RCMP after the accident in which he said the van was going 120 km/h.

He also never mentioned being distracted in the police statement, Marcoux said.

Maxwell-Smith, who only has a B.C. learner's driver's licence class 7, is not legally allowed to drive with more than two passengers and must have zero alcohol in his blood, the court heard.

Maxwell-Smith said breaking those rules was not a conscious thought on his part that night.

He felt it was his duty to supervise everyone else, he said.

He currently has a full licence to drive in Britain.

Following Maxwell-Smith's testimony, the court heard from an expert witness for the defence, who questioned the results of tests done on Maxwell-Smith's blood alcohol level following the crash.

Two breathalyzer tests performed around two hours following the crash found Maxwell-Smith's blood alcohol content to be 0.11 and 0.12 — above the legal limit of 0.08.

A toxicology expert with the RCMP lab in Vancouver testified earlier that would mean his levels at the time of the crash were between 0.13 and 0.15.

On Thursday, defence expert Dr. Mariah Wallener, a professor at the University of British Columbia (UBC), told the court the RCMP's method of estimating a person's blood alcohol content after a crash can be unreliable because the math used does not allow enough time for the person to reach his or her peak alcohol concentration level.

The RCMP's method requires that a person not have had a drink for the 30 minutes prior to crashing.

Wallener argued that number should be closer to 90 minutes.

Without allowing for enough time, the results of the math could lead to inaccurate results, she said.

The case wrapped up with closing statements this morning.

Maxwell-Smith's lawyer, Gord Coffin, argued that the Crown had not done enough to prove his client was impaired enough to affect his ability to drive and cause the crash.

He pointed to multiple witnesses who testified that Maxwell-Smith had no trouble walking or talking or understanding what was going on around him.

The only sign of alcohol consumption was the smell of liquor on his breath.

That smell is not enough to prove the liquor caused him to be impaired, Coffin said.

The fact that there was a crash is also not evidence of impairment, the lawyer argued.

The road's condition, combined with a distraction, is another reasonable explanation, he said.

"An accident sometimes is simply that,” he said. "An accident.”

Marcoux disagreed.

He reminded the court of the Crown's toxicology expert, Verna Mendes, who said a person can be impaired before showing outward signs of intoxication.

Many things Maxwell-Smith did point to impairment, he argued.

He drove past eight signs warning of the upcoming construction.

A safe driver who was not impaired would know to slow, Marcoux said.

Choosing to drive that night even with the restrictions on his licence, also shows impairment, he said.

Marcoux argued Maxwell-Smith was minimizing the amount he drank.

The toxicology expert's report said more than the three beers Maxwell-Smith has admitted to drinking would be required to get to the blood alcohol readings she found, Marcoux said.

Coffin argued that could just as easily point to flaws in the testing.

Marcoux suggested the friends who testified for the Crown to Maxwell-Smith's drinking may be lying to protect their friend.

Judge Nancy Orr told the lawyers she would try to have a ruling by this afternoon.