And you know it was because he smokes, how? Also, what one considers a foul smell is entirely subjective. Many people find the smell of fields freshly dressed with manure to be foul, I personally look forward to it and do not find it offensive in the least.
I know it was because he smokes because the foul smell smelled like the bottom of a stale ashtray. A former smoker never forgets that smell. Yuck!