John Cooper, of Berwick, near Eastbourne, told the inquest how he was travelling in the same eastbound direction as Mr Llewelyn on the A27 when he saw the blue Renault pull out.
Mr Llewelyn - who featured in all but two of the Bond movies - was on his way to sign copies of his biography when his Renault Megane and a Fiat Brava collided head-on on the A22 at Firle, near Eastbourne, East Sussex.
The 85-year-old star, from Bexhill, who had just announced his retirement from the world of 007, was airlifted to Eastbourne District General Hospital, where he died three hours later.
John Cooper, of Berwick, near Eastbourne, told the inquest how he was travelling in the same eastbound direction as Mr Llewelyn on the A27 when he saw the blue Renault pull out.
He said: "The car went onto the wrong side of the road. I saw an oncoming car and then a few seconds later a collision.
"The manoeuvre by the blue car was a firm one. There was nothing hesitant about it."
Mr Llewelyn's vehicle went into the front of a hire car being driven by Rhys Morgan.
Mr Llewelyn's son Ivor told the court how his father, born in Newport, Gwent, was on his way back from Wales to sign copies of his biography in Alfriston, East Sussex.
Mr Llewelyn said: "For his age he was remarkable. He travelled a lot."
'Wrong side of road'
Pathologist Dr Christopher Moffat told the inquest that although there was sign of heart disease, there was no evidence to suggest Mr Llewelyn had suffered a heart attack.
He had a successful bypass operation several years before to ease his condition.
Coroner Mr Craze concluded: "It would appear Mr Llewelyn was wholly on the wrong side of the road. The overtaking manoeuvre occurred at a time when it was not appropriate."
Solicitor Mark Braid, representing Mr Morgan, refused to comment on whether his client would be taking any further action.
Mr Morgan received a broken leg, pelvis and ribs, cuts and damaged eyesight.