A Halifax Regional Police officer is fighting to get his rank back after he allegedly used excessive force during a traffic stop last year.

Const. Matthew MacGillivray was demoted after a video showed him ripping off his nametag and throwing it at a couple during a traffic stop.

Graham Labonte recorded the video of his wife, Angela Acorn, and officer MacGillivray in September 2015.

“You have to (expletive) calm down,” yelled Acorn.

The video then shows Labonte asking officer MacGillivray for his name.

“I told you my name is Sgt. MacGillivray. You’re both under arrest,” MacGillivray said in the video.

They’re from Prince Edward Island, but were on their way to a chronic care appointment in Halifax.

The couple said they witnessed a police officer driving erratically, and were eventually pulled over. They say at the time, they didn't know why.

Labonte called 911.

“We're being pulled over by a hostile cop,” said Labonte during the 911 call. “He's yelling at my wife. He's got her by the hands. His name is M. MacGillivray. He's threatening to draw his weapon. I'm totally unarmed. I'm videotaping him. He's treating my wife like a total criminal and he's using her as some kind of shield when I am totally unarmed. This is disgusting."

MacGillivray's lawyer suggests the couple was resisting arrest.

On Monday, Acorn testified at a Police Review Board hearing.

"I just don't know why he kept hurting me,” Acorn testified. “I didn't do anything, and I begged him to stop hurting me."

MacGillivray was never charged with a criminal offence, but was demoted from a sergeant to a constable.

“Basically, the heart of it is that we feel he used force when he didn't have to do so,” said Halifax police lawyer Katherine Salsman.

MacGillivray is appealing that decision.

“We can say no, that's too heavy-handed. We can say no, that is correct. We can say there should have been nothing. We can impose a completely different penalty,” said Jean McKenna, chair of the Police Review Board.

The Police Review Hearing does not involve Nova Scotia’s Serious Incident Response Team, which conducts criminal investigations when there are allegations of serious injury involving police.

The director says Acorn's injuries do not meet the definition of serious, which usually involves broken bones, or worse.

Acorn was taken to hospital and said she suffered soft tissue damage, bruising and swelling.

"My whole life's been turned upside down by these events," Acorn testified. “I find it very hard to trust. When I'm out and I see a police officer or car, I can barely breathe."

The couple received three tickets for speeding and failing to obey a peace officer, but all were withdrawn.

Four days have been set aside for the hearing, which will continue on Tuesday.

Officer MacGillivary has not yet testified at the hearing. His lawyer has declined to comment while the hearing is underway.

With files from CTV Atlantic’s Kayla Hounsell.