'A thing of' is a very Irish way of describing an inanimate object, usually a container or packaging of sorts. Be it down to laziness, or actually not knowing the name of what the object is, this expression has many uses.
Someone doing something that they shouldn't be doing e.g. a ref giving a bad decision at a game, a child playing with a box of matches, a garda pulling up someone for pissing in a dark alley etc.
