But that's little comfort for the family who are still nursing their wounds.
Lewis Owen, a graphic designer who lives in Singapore, was with his mum and dad celebrating the father's birthday on the evening of the assault.
He said he sees his parents, Rosemary, 65, and father Lewis Sr, 68, twice a year.
The next time they definitely won't be catching up in Thailand.
"I'm not going back to Thailand again," he told The Mirror from Singapore.
"Mum and dad won't be either. Never, ever again."
Mr Owen's injuries required 16 stitches in three areas of his head.
His dad needed six stitches in his forehead and suffered heavy bruising and two black eyes in the assault.
His mother underwent several operations to help reduce swelling on the brain.
Both are "on the mend" and are expected to return to the UK next week.
Mr Owen said police had not showed him the CCTV footage initially because "it was too violent".
He only realised "how badly" they were beaten up when he watched it yesterday morning.
"We were all unconscious. My mum did not even realise she had been kicked in the face. I did not know my head had been stamped on," Mr Owen told The Mirror.
"It was just out of the blue. None of us were drunk - we had just had a merry night and were going home."
Mr Owen said he didn't know why they were attacked.
"I didn't know them, it was just random," he said.
In the video the family is seen walking down a crowded street amid festivities for the Thai New Year.
An altercation breaks out with a group of men on the street who punch all three in the face, kick their bodies and stomp on their faces in an attack that lasts about two minutes.
Police Colonel Chaiyakorn Sriladecho said it started after "the son accidentally bumped into one of the Thai men."
The attack stops only when all three victims are seen lying apparently unconscious on the ground.
As the Thai gang disappears, bystanders come to their aid.
"We have now arrested all four suspects," Chaiyakorn said.
Three of the men were arrested within days of the incident and the fourth on Thursday, he said, identifying them as in their 20s and 30s.
"The men say they are sorry and that they wouldn't have done this if they weren't drunk," he said.
The incident is the latest blow to the country's image as a welcoming tourist paradise.
In March, four French tourists were assaulted on the island of Koh Kut as they walked to dinner. They included a mother and daughter who were both raped.
Two British backpackers were murdered on the island of Koh Tao in 2014.
Autopsies showed the couple, a young man and woman, had been severely beaten and the woman raped.
Two Myanmar migrants were convicted of the crime based on DNA evidence that rights groups say was questionable.
- news.com.au
