I like SD's points. However, couldn't it be that he just didn't like ZaZa and just wanted to make their meeting "less casual" than it would've been if he accepted that cigarrette?

PS: I haven't seen part III in ages and I can't remember if he does or does not smoke in the entire movie....If he had quite, than an associate/representative/ally like Zaza would've known that his Boss does/does not smoke....