I simply don't understand the reasoning of some posters who conclude the green pickup was to blame, partially or otherwise.
The white truck was following on a single carriageway and should have been driving according to the conditions prevailing. He clearly was driving too fast and was taken by surprise by the green vehicle turning right. If he had been travelling at a proper speed and had kept a decent interval then the incident may not have occurred although being asleep at the wheel is always a possibility.
100% the fault of the white truck which no doubt was up the backside of the green pickup. They tailgate all the time, everywhere in Thailand. All part of their imbecility and chronic inability to foresee consequences.
Also, he no doubt had the wrong amulet that day.