"Have fun doing that"

REAL TRIMET SUPERVISORY REPORTS
Operator observed smoking at door of bus at Tigard TC.  I approached the operator to confirm that he was smoking.  He cupped his cigarette in the palm of his hand to conceal it from me.  I asked him if he was smoking and he admitted it.  I advised that he knew the rules and that passengers are being cited and fined $175 for smoking.  He started to walk away from me and I asked him to come over to discuss it with me.  He never did put the cigarette out.  I advised him that I was going to write him up.  His response "You have fun doing that" and walked away.