An Ontario judge has acquitted an Ottawa police officer charged with impaired driving, and chastised the RCMP officers who pulled her over for their "atrocious" and "disturbing" note taking.

In May 2014 RCMP Const. Gary Lee pulled Marie Josee Seguin over for erratic driving on the Highway 417 eastbound off-ramp at St. Laurent Boulevard.

Seguin, who was off duty at the time, was later charged with impaired driving and failing to provide a breath sample.

Seguin argued that the stop and her detention were unlawful. She argued the RCMP does not have the authority to stop drivers on Highway 417, nor is there a bilateral agreement between the RCMP and Ottawa police for that stretch of road.

In his ruling Justice Allan Letourneau said he believed Lee pulled Seguin over because he feared for the public's safety.

But Letourneau went on to characterize Lee as "a very poor witness," and scolded all four responding RCMP officers for their "atrocious" note taking. In court even Lee admitted he would grade his own notes that day with an "F."

Alleged drunkenness called into question

The judge chastised Lee for filing his general report more than 15 hours after the incident. When pressed about why he omitted certain details in his notes, Lee said he didn't remember them until he testified.

For example, he wrote that Seguin fumbled to find her ID, but failed to mention that the licence was behind other documents in her wallet.

"The extent of the failure of all four officers to comply with their own force's note taking requirements is astounding and disturbing," wrote Letourneau.

"Contemporaneous and comprehensive notes are especially important in drinking and driving cases where often there is no independent evidence available to corroborate the testimony of police officers."

The judge questioned if Seguin was in fact inebriated when "no other witness testified that she was very drunk."

Seguin told the responding officers she had three drinks, but they never asked her when and over what time period, the ruling says.

"She did not stagger, stumble, stray or wave while walking with him back to his cruiser," Letourneau wrote, dismissing the refusal charge.

He did rule that both the stop and investigative detention were lawful.