The motorist who caused three deaths by driving the wrong way down the motorway had a deadly brain cancer that can cause confusion.
John Norton had been receiving chemotherapy for the cancer, which had spread from the bladder, shortly before the accident happened, pathologists told the inquest.
He died along with his 87-year-old partner, Olive Howard, and former Soldier Stuart Richards when their subaru and caravan collided with Mr Richards Ford mondeo on October 15 last year.
Mr Richards, who lived in Stockport, Manchester, had served in Iraq and Afghanistan before becoming a health and safety officer with The Emerson Group.
The retired foreign exchange banker and his partner left their home in High Wycombe that day to visit friends in Slimbridge, Gloucestershire.
Three people died in the horror crash near junction six of the M40 in Oxfordshire last year
Before the crash, the inquest held at Oxford coroners' court heard he had been acting strangely.
Patricia Young, who met the couple 20 years ago at Companions Caravaning Club, said Ms Howard had told her Norton was 'not himself' over the phone the day before the crash.
'She couldn't do anything right,' Ms Young told the inquest in a statement. 'The crumpets were not cooked right, the coffee was not hot enough, even the marmalade tasted funny.'
'I heard her ask him if she had upset him and I heard him shout, ‘No! I told you, it is nothing to do with you.’ I’d never heard him raise his voice to anyone.
'I had a conversation with John who told me he’d been to the eye hospital and was pleased with his new glasses. He was quite curt, quite sharp. Unlike John.'
Dr Nicholas Hunt found evidence of the cancer in Norton's brain during a post-mortem.
'An examination of the brain showed significant involvement with bladder cancer that had moved to other parts of the body,' he told the inquest.
'With symptoms including effect on behaviour and hazard appreciation, is clearly, albeit indirectly, of great significance in terms of his own death and others involved in this collision.'
The car in the middle can be seen driving the wrong way on the M40 in Oxfordshire last year
Other motorists were forced to swerve out of the way as the car and caravan approached them
Dash cam footage shows the shocking moment the subaru with a caravan attached went down the motorway in the fast lane, causing other cars to swerve dangerously to avoid it.
Norton had ignored no-entry signs at junction 8 of the northbound carriageway, near Wheatley, Oxfordshire, and entered the wrong side of the motorway.
He pulled into the fast lane and travelled at a speed of 60 to 70mph as other cars swerved out of the way in alarm, until it hit the Ford mondeo.
Alistair McFarlane, who was
