well, he's probably not entirely up to scratch on legal terminology, especially if he's, er, studying drugs all day. But he's only suggesting possible principles, not drafting legislation, so we could cut him some slack. (That peculiar headline, Drug users 'should face penalties', doesn't exactly clarify matters.)
My guess is he's just saying there's no point in jailing people for taking drugs. If you're in the business of distributing drugs, yes, losing your licence could hurt - imagine the indignity of a drug lord having to take the bus, a bus he hasn't even been able to pimp. And you could argue that someone smoking a spliff in his bedroom is causing a lot less hassle than someone parked on double yellow lines. You can disagree with this, of course, but it seems a reasonable enough suggestion to put forward.