He hasn't quit. He's smoked all his adult life plus 3 years before that.
He can no more stop smoking than UNKewlJ can stop lying.
Getting back to my example, I stopped all casino play for a decade or so. Went to Vegas during that period many times. Didn't play a nickel. Didn't stop because I lost, stopped because I wanted to concentrate on my career. Once that got to the point where I had boatloads of money and time to spare I resumed casino play.
Let's say I stop again.
What does that mean, if anything?
If I'd played in casinos since I was 15, every single day, with only a smattering few weeks of stopping here and there could I say that I can stop?
In one example you have someone who stopped for a decade or more. In another one who stopped for only a few weeks. Does one cessation mean more than the other, if the activity is maintained?
Point being that stopping and then starting up again shouldn't be the criteria for whether or not someone is capable of stopping for good.