A man whose boat was struck by a vessel operated by Linda O'Leary on a summer night nearly two years ago testified Monday that he heard an engine revving in the moments before the fatal collision.

Irv Edwards, a California-based physician whose cottage is in the central Ontario community of Seguin, said he and some friends and acquaintances were out on his boat the evening of Aug. 24, 2019 to look at the stars following a dinner party.

It was a "warm, clear and cloudless" night, he recalled, and quite dark when the group set out from Hamer Bay onto Lake Joseph around 10:30 p.m.

They spent some time identifying constellations and trying to determine what was a shooting star and what was a satellite, and at some point there was some "good-natured joking" about golf tournaments, he said.

Edwards said he heard a boat engine revving "at high speed" about 20 seconds before his boat was struck around 11:30 p.m.

"It did not register with me as being alarming because I assumed that the boat coming would pass on one side or the other ... so I kept staring at the stars until this horrific collision occurred," he told a Parry Sound, Ont., court Monday.

"It was a huge impact that pushed the boat backwards, I felt, substantially. It was not, by any means, a small tap."

Linda O'Leary, the wife of celebrity businessman Kevin O'Leary, pleaded not guilty Monday to one charge of careless operation of a vessel under the Canada Shipping Act.

An agreed statement of facts read in court said she was at the helm when the boats collided.

Gary Poltash, 64, from Florida, died at the scene, while Suzana Brito, 48, from Uxbridge, Ont., died in hospital a few days later. Three people were also injured.

Poltash and Brito had been sitting at the front of the boat, facing back towards the vessel, Edwards testified. His cousin had also been standing near that area, he said.

Immediately after the collision, Edwards said he and others on the boat turned on their cellphone flashlights in order to see more clearly.

Poltash's neck was "distorted and cocked to the right side," and he had a bloody gash above his ear that "clearly meant" he had a fractured skull, Edwards said.

Brito's neck was not as distorted and a little blood could be seen coming out of her nose or mouth, he said. Both were unresponsive, as was Edwards's cousin, who had been propelled face down onto the boat's floor, he said.

The agreed statement of facts said Poltash and Brito died as a result of blunt force trauma from being struck by a boat.

Edwards said a male and female voice could be heard from the other vessel, though he said he was never able to see who was speaking.

The woman said something to the effect of "we struck someone" or "you struck someone," before the man called out to ask if everyone was OK, Edwards recalled.

The doctor said he replied that they had people injured and unconscious on board and would be going to shore to tend to them. He did not recall hearing a reply.

Calls were made to 911 as they headed back to shore, he said.

Edwards told the court he suspected "very little" could be done for Poltash in light of the man's head injury, and his friend's heartbeat stopped shortly after they docked. Poltash was given CPR but paramedics declared him dead around 12:30 a.m., he said.

Whether Edwards's boat had its lights on in the lead-up to the crash is likely to form a key question in the trial, and court is expected to see security video from both the Edwards and the O'Leary cottages.

Edwards testified Monday he handed over the operation of his boat to his friend Richard Ruh earlier because he wanted to be able to enjoy the stars.

He told the court the boat's lights -- a strip of LED lights on both sides of the bow and a dome light at the top of the tower -- were on when he was captaining, and that he did not see any change after switching places with Ruh.

"It was dark at night and they needed to be on," he said.

Ruh, of Orchard Park, N.Y., was also charged in the incident. He faced one count of failing to exhibit a navigation light while underway.

Kevin O'Leary, the former star of the popular CBC show "Dragons' Den," also stars in the ABC show "Shark Tank." He ran for the leadership of the federal Conservatives in 2017, but eventually dropped out of the race.

This report by The Canadian Press was first published June 14, 2021.