I'm just asking, are you saying the driver intentionally caused his engine to belch diesel exhaust just because he was passing the line of cyclists?
If so, you need to know a bit about older diesels. They always smoked under load. The truck is climbing a hill, and I guarantee you, it's belching smoke just like it would when pulling away from a light on a city street.
As for whether he was "enjoying" pasting them with fumes and recorded, sure, I agree, seems like a bizarre personal enjoyment. Is it possible he was filming the scenery?