The Finnish man was also instructed to pay the airline’s legal costs in the judgement handed down by Helsinki District Court.
The incident took place on a flight from Helsinki to Vietnam in 2017, and started after the passenger attempted to use a Finnair gift card to pay for in-flight purchases, the court heard.
The man then went to one of the aircraft toilets; loud banging noises could be heard while he was in the cubicle.
A member of cabin crew went to check the toilet after he had vacated it.
“I have never in my career seen so many broken parts in a toilet, and it smelled of vomit and urine,” the flight attendant told the court.
A towel rack had been ripped from the mirror, while it appeared attempts had been made to break the cabinet under the sink, with one door broken off and the wall behind it having sustained damage in the process.
While the passenger admitted to causing the damage, he denied it was intentional.
“I wobbled due to turbulence, and I grabbed the mirror cabinet,” he told the court.
He added that he had been drinking alcohol and taking sedatives.
His assertion was contradicted by four witnesses, who all stated there had been no extreme turbulence during the service.
Meanwhile, a Finnair safety director outright denied that turbulence could have been responsible for what occurred.
“It would have been necessary to use extreme force to remove the towel rack and the cabinet door,” he said.
The man was found guilty of endangering the safety of those onboard and the court ruled that he was still liable despite having taken sedatives and alcohol.
“The incident could have become very dangerous if the damage had affected the aircraft's cabin pressure,” said the ruling.
The defendant is free to appeal the verdict at a higher court.