An Army veteran was killed after a single punch by a security guard in Thailand, an inquest has heard.
Mike Jones-Matthias, 55, was on a work trip when he was hit outside the Mandarin Agogo bar in Pattaya after being accused of not paying his bill.
Phumphat Tanosingh was cleared of grievous bodily harm in a trial in Thailand.
The inquest in Pontypridd heard Mr Jones-Mathias died ten months later of pneumonia and traumatic brain injury.
It was shown CCTV footage of him leaving the bar in May last year and walking onto the main street outside, followed by two Thai men.
The footage showed him throwing a punch to the air before being hit to the floor in a single strike.
The inquest heard he was at the start of a three-month work trip and went to the bar alone on the way back to his hotel on 17 May 2018.
His wife, Veronica, told the inquest: "For the record, I know my husband would never have left a bar without paying a bill.
"What could have happened in that establishment that could make that punch lawful?"
Mr Jones-Mathias was taken to hospital in Thailand, and had surgery for damage to his right frontal lobe. He was flown to University Hospital of Wales six weeks later.
He died on 24 March after his health deteriorated.
Professor Phillip Smith, of University Hospital of Wales, gave a cause of death as pneumocystis pneumonia and traumatic brain injury.
Mr Jones-Mathias, from Cowbridge, Vale of Glamorgan, graduated as an officer in the Army in 1984 and served in the first Gulf War.
He later worked as an operations manager for heavy lift and installation engineering projects in the Middle East.
Acting senior coroner Graeme Hughes rejected the family's request for a conclusion of unlawful killing.
Recording a narrative conclusion, he said: "The deceased died as a consequence of complications arising from head injuries sustained following a punch to the head."