The article doesn't say that he was passing it, but 'he swerved to the right to miss a motorcycle with sidecar.' That suggests to me that the motorcycle was going the wrong way, perfectly normal in Thailand where which side of the road you drive on is optional, especially if you are on a motorcycle. If that is the case then the motorcyclist needs to be prosecuted for causing death by reckless driving. But I'd guess he/she just vanished from the scene.
Or, I might be wrong
"Or, I might be wrong".
Nah, surely not.
"...he swerved to the right to miss a motorcycle with sidecar...".
Webfact's version of the original report does state that but the linked original gives an explanation of what actually happened.