It may have nothing to do with the smoking at all and just is a coincidence. . but I know a lot of peole who FIRST start smoking and smoke heavily will puke because their bodies are not accusomed to the chemicals. They can become dizzy and faint adn puke. . He was prob. cleaning all the crap and chemicals outta his lungs and when he started again his body rejected it. The body naturally expells harmful substances its not use to or the person hasnt used in a long time.