If that does not embarrass him enough to change his behaviour, at least it will have been a gesture of sympathy for the poor, embarrassed children he thinks he is supporting.
Our stories over the past six weeks have given plenty of testimony to the harm his sort of "support" can do. And it is not confined to rugby. All White Ivan Vicelich said he might not be playing football today if he had been subjected to the sort of sideline behaviour he sees directed at children in teams he is now coaching.
What possesses parents to shout abuse from the sidelines at a 10- or 11-year-old for a misdirected pass or a run in the wrong direction? Do they imagine that is how sport is learned? Are they trying to impress others present with their supposed knowledge of the game and their competitive aggression? Or are they just having fun at the kid's expense?
Whatever these idiots think they are doing, they are most likely turning their child against the game and almost guaranteeing they give it up as soon as they can.
Boys in particular have a deep-seated need to measure up to their father's hopes and failure can be hard to overcome.
The abusive sideline parent is probably compensating for his own failure at the game, or any game, in his youth. Good sportsmen and women as a rule do not seem to be put excessive pressure on their children to succeed in the same way.
Our series has uncovered some appalling incidents, such as a father at netball telling his daughter to punch another girl in the face to put her out of the game, or the coach who headbutted a man he asked to referee their game just two weeks ago.
But it is the ordinary aggressive undertone of the sideline culture that breeds the excesses.
Silence, urged by one football coach, is not the answer. Enthusiastic support on the sidelines ought to be encouraged. But it needs a better language than "hit 'em hard", "smash 'em", "take him out of it". This is how many armchair followers of rugby or league think a game is played.
Change, as usual, has to come from the top. Players such as Richie McCaw and Dan Carter, who are fronting the Applaud campaign, do not play the man. Nor does Richard Kahui, Warrior Manu Vatuvei, Silver Fern skipper Casey Kopua or others featured in our Sideline Champs series. They would not be nearly as effective if they did.
Sport is supposed to be fun. It is about striving for success and trying your best. It is not life or death, not a test any child needs to pass.
It is, though, a test of maturity and character on the sidelines. Not a particularly hard test: cheer loud, cheer fair, cheer proud.
