If the tap is in your lot airspace, then it is your responsibility.
Yes, there is a disclaimer to the “Who’s responsible ..” document, but you can bet your life that if this issue ever went to the Tribunal, the adjudicator would have a copy of the guide next to them. It may not have any defined legal standing (unless it has been accepted by your strata scheme via a by-law) but it is held as being pretty much definitive.
For $20, I would save myself all the hassle and buy the tap.