But the story about the woman's condition was all a trick -- a ruse to flush out the driver, the report said.
The OPA says the driver's friends reported that he grew worried in the days after the crash, thinking that someone possibly died in the wreck.
Less than a week after the crash, his roommate found the man dead in his room. The OPA now says that the police officer's lie contributed to the man's death.
"The ruse ultimately contributed to the subject's subsequent suicide," Andrew Myerberg, the civilian director of the OPA, said in a letter to Seattle Police Chief Carmen Best.
In November, the OPA released a report, first reported by The Seattle Times
on Thursday, detailing the incident and its investigation into allegations of police misconduct. There were no injuries reported after the crash, the OPA says, and investigators looking into the crash were only expecting that their colleagues would get the driver's insurance information.
Neither the driver nor the officers have been identified.
Seattle Police Department said in a statement Thursday that the police officer was suspended six days without pay for using a ruse during the investigation.
"The officer's actions did not meet SPD's standards of acceptable use of discretion and were not consistent with the standards of professionalism or training," the police statement said.
Officer said ruse was 'reasonable and appropriate'
The OPA report says that when asked about the incident, the officer, identified in the report as NE#1, told the watchdog that he believed it was "reasonable and appropriate" to use a ruse.
"Specifically, he asserted that the ruse was needed to get information relevant to a criminal investigation and, while there was no exigency, there was an ongoing threat to public safety. NE#1 denied that the ruse shocked fundamental fairness," the report states.
The officer noted that it was "regrettable that the Subject committed suicide, he was not ultimately responsible for the Subject's actions."
'It's a lie, but it's fun'
In his report, Myerberg said there was "insufficient need" to use a ruse and "it is clear that the ruse was, at least in part, a cause" of the driver's suicide.
Before arriving to the house, the officer told his partner that he would use the ruse if they found the suspect and said "it's a lie, but it's fun," his partner recalled, according to the OPA report.
The officers left the home of the the driver's friend after she gave them his number. It's unclear if they tried to call the driver.
After the driver's death, his friends and mother began looking into the hit-and-run. The friend who was contacted by police filed a complaint with the OPA in March 2019, prompting the watchdog investigation.
During the investigation, one of the driver's friends told the agency that at some point everyone believed the driver "had hit and killed someone but that he did not remember it."
"He didn't remember the incident and was freaking out," his roommate told the agency, according to the report.
Myerberg said the officer's actions "shocked the conscience" and were inconsistent with the community's expectations of the officer's conduct.
The officer's partner told investigators she knew there were no injuries and she believed there was no need to use the ruse, the report said.
The police department said Thursday it agreed with the watchdog findings, adding that it provided in-service training to all sergeants, officers and detectives on the appropriate use of ruses during criminal investigations.