The article is poorly and vaguely written, like so much of our newspaper output here.

It doesn't say that he got the 75 hours 'for' farting at a policeman - and I'd struggle to say what specific offense it would be, and - in order to be sentenced for the farting it would need to be an articulable, specific crime.

But he crashed a car - which isn't an offense in and of itself - and then blazed a joint in front of the police, which of course is.

If I were ascribing more intelligence to him than perhaps he deserves, I could contrive that he was driving stoned (which is considered a serious offense, particularly in light of the crash), and he concluded that by smoking in front of the police, he could claim that he was not stoned whilst driving, but that he became so afterwards. There's nothing to gain from the police doing a post-accident drug test under those circumstances as it won't fly in court for a drug-driving charge.

More likely though, he was just a belligerent bell-end and got what was coming.