nope definately no overreacting, i would have gone NUTS if that was DF.
i have cracked it several times at people for blowing smoke on DS, once when he was only a couple of months old. its something that is learned thru seeing as well as smelling/breathing in so we try to avoid any smoking, thankfully only one cousin smokes and thats it and no friends. my mum used to but has quit thank god.