No “right-thinking police officer” would have taken the actions a Hanover officer did in the moments before a collision that left a man with a serious brain injury, the head of Ontario’s Special Investigations Unit says.

Nonetheless, SIU director Tony Loparco has cleared the officer of any criminal wrongdoings in connection with the crash, saying the officer’s actions didn’t rise to the level of dangerous driving.

The April 1, 2017, collision ended with a 27-year-old man being airlifted to hospital, having suffered what the SIU describes as “near-fatal” brain injuries. A large portion of his skull was removed. He remains in hospital to this day and may never recover.

SIU investigators found that police were notified that night about an ATV driving through Hanover with its lights on. Ontario’s Highway Traffic Act makes it illegal to drive an ATV without lights at night, while Hanover’s bylaws ban operation of ATVs on the town’s streets.

One police officer spotted the officer and followed it through a residential neighbourhood. At the intersection of 10th Street and Sixth Avenue, the SIU found, the ATV operator ran a stop sign and collided with another vehicle. The 27 year old was ejected from the ATV and landed head-first on pavement.

In his report, Loparco noted that the officer broke provincial regulations by starting and continuing a dangerous pursuit of the ATV over relatively minor infractions, as well as Hanover Police protocol, which states that ATVs and motorcycles should never be pursued in the town.

“I cannot imagine that any right-thinking police officer would think that it was necessary to pursue an ATV in a residential area, at high rates of speed, while following very closely behind the vehicle, in poorly lit conditions, while the ATV is without the benefit of headlights, in order to investigate the driver for a bylaw infraction and/or an equipment infraction,” he wrote.

“Further, I cannot imagine any reasonable person believing that issuing a ticket for a bylaw infraction and/or an HTA equipment infraction would have outweighed the risk to public safety of continuing to pursue an ATV at the speeds which the (officer) did.”

Much of the pursuit occurred at relatively normal speeds, the SIU found, although the ATV at one point quickly accelerated to about 80 km/h, with the cruiser following suit. It is believed that the cruiser then slowed again about 10 seconds later, having travelled about 300 metres at the higher speed.

One person told investigators that he jumped out of the cruiser’s path, believing he would have been hit by the vehicle otherwise.

Despite voicing what he called “strong disapproval” of the officer’s actions, Loparco stopped short of finding reason to lay a charge of dangerous driving against him. He said the fault ultimately lay with the ATV operator who made the “voluntary decision … to try to outrun police” and ultimately caused the collision by driving too fast and running a stop sign.

The SIU investigation involved interviews with four police officers and more than 20 civilians who witnessed some of the events of that night. The officer who was pursuing the ATV declined to speak with the SIU or provide investigators with his notes.