IMHO, mik5 wins the prize for the most accurate answer – he’s basically quoting the Mishna Brura (although I think the MB may have only said that bi’shas ha’dchak). However, a very strong argument can be made that that was only true in the days of the MB when smoking was not known to be dangerous; but today, it is almost certainly always assur.
sushibagel: Some topics tend to make people fly off the handle, and irrelevant rants are a common effect. As you’ve apparently learned the hard way.