In laying out the Crown's argument against a local bouncer charged with assaulting a customer, prosecutor David McWhinnie called it "a one-punch case" Monday.

There is little dispute, he told a Yukon Supreme Court jury, over whether the punch actually happened. What the jury must decide is if the punch was warranted.

Apart from deciding on the legality of the blow, the six men and six women of the jury may also have to piece together the scene of the alleged crime without any help from the men who say they were attacked - neither one remembers what happened on Jarvis Street that night in October, 2007.

In fact, they didn't even contact police about the incident - one of their mothers called from Ontario after hearing her son was in the hospital.

Clinton Derkson is charged with one count of basic assault and one count of aggravated assault for an incident which occurred outside Coasters Bar and Grill.

Derkson, who was 22 at the time, was working as a doorman at the popular Whitehorse bar. It was a quiet Tuesday night at Coaster's, and no more than a dozen customers were in the bar, among them a pair of diamond drillers from Ontario.

The two arrived early in the evening, at around 7 p.m., and stayed until closing time, by their own account drinking steadily for more than seven hours.

They were a quiet pair, according to Troy McFadyen, who was working behind the bar that Tuesday, and they didn't make much of an impression until 2 a.m., when their server asked them to finish up their drinks and go.

One of the two men, Brent Lebrasse, testified Monday that they were asked to leave three times, by three employees, at the end of the night.

He remembers getting "pissed off" after being told to finish up and get out a third time. He remembers telling Derkson to "F-off" when the bouncer approached them and asked them to leave. He doesn't remember Derkson touching him, or returning the insult.

He does remember eventually getting up and walking to the door - and then nothing.

The next thing Lebrasse can describe is waking up in their shared hotel room in the 2-0-2.

His friend, Joshua August, was in the bathroom, spitting up blood, Lebrasse said. His own jaw was throbbing and when he looked in the mirror, he saw "it was kinda hanging to the left, so I popped it back in and it was tender for a few days."

August told a similar tale, but with fewer details. He said he didn't remember anything about getting upset or swearing at the staff.

He did remember, however, being treated for a jaw which was broken in two places, suffering a fractured skull and eating through a straw for months.

Other witnesses for the prosecution filled in the gaps in McWhinnie's case.

The bartender on shift that night said he asked the two to leave and they resisted. After he returned to his post, the bartender said, he could tell from the look on the bouncer's face that the men were saying something offensive to him as they left the bar.

The Crown's only eyewitness of the actual punch told the rest of the story.

The last person to take the stand for the prosecution was working at the 2-0-2 off sales on the night of Oct. 2, 2007. She finished up work at about 12:30 a.m. and headed to the bar for her free "staff drink."

She was there until the end of the night, she said, and was one of the staff members who told August and Lebrasse it was time to go.

"Please leave, the bar is closing," she remembered saying to the men.

They responded by saying, "When we come to Whitehorse and spend our money, this is our bar. We spend the money, it's ours."

The three on-duty staff members, along with three other off-duty employees who were at the bar, all asked them several times to leave. It took more than 20 minutes to finally get them out, she said.

Once the two had left, a few of the bar employees went outside for a cigarette. August and Lebrasse were still in the street, standing at the entrance to the hotel.

"They were so intoxicated, they didn't know if they were coming or going," the woman recalled. The two came staggering over to the smokers, still talking about the money they had spent and protesting their expulsion.

At the same time, the off-sales woman noticed that inside, the waitress was trying to prevent her boyfriend from coming out the doors.

He eventually shook her off and came bursting out. A scuffle ensued between the boyfriend and Lebrasse, she said. Then - out of nowhere - Derkson punched August in the side of the head.

"It was very unexpected," she said, noting that neither Derkson nor August had been acting aggressive or expressed any interest in fighting. August was simply watching his friend and the other man "flailing around" when Derkson hit him, she said.

August dropped to the ground, hitting his head on the sidewalk, and was knocked unconscious.

It all happened in a matter of seconds, she said. There was no blood coming out of August's head and Lebrasse was still on his feet.

"I remember saying: 'Let's go inside. Get inside,'" she told the court.

Nobody called an ambulance for the unconscious man and a short time later, she noticed that August and Lebrasse were gone.

None of the other people who were outside the bar that night testified for the prosecution and none gave signed statements to police.

The trial is overseen by Justice J.E. Richard, a visiting judge from the Northwest Territories.