The City midfielder who has played for Australia reacted as though he was hit by a ton of bricks in the immediate aftermath of a tussle with his Adelaide United counterpart Isaias.
The Spaniard 'slapped' Kilkenny with a brush of his palm after being awarded a free-kick and City's new signing promptly fell to and rolled on the ground and clutched his face in a move that could be seen as though he was trying to get Isaias sent off.
As Kilkenny lay motionless on the deck Isaias sheepishly protested his 'innocence'.
Kilkenny amazingly was not even booked by referee Chris Beath and the match review panel need to have the power to come down hard on the player and make him an example of how footballers should not behave.
The offence was not serious enough to warrant the MRP's intervention.
There have been some rare instances of play-acting in the last two A-League seasons but the unpleasant incident in the 36th minute of the first half left a sour taste, especially since it was shown nationally on SBS.
The indiscretion was a great shame because the match itself which City won 2-1 thanks to a splendid Bruno Fornaroli double lived up to all expectations and was a marvellous advertisement for the competition.
However Kilkenny's was the sort of behaviour that drives fringe fans away from the game and gives ammunition to those who see football as a platform for blatant cheating.
Trying to get a fellow professional sent off with sneaky methods is as unsportsmanlike and reprehensible as can be. It is worse than a dangerous foul such as Fernando Brandan's on Tarek Elrich that deserved a straight red or a blatant dive to earn a penalty.
One hopes that Kilkenny, who has been involved in a similar incident in the past playing for Preston North End against Bradford City, may have had a rush of blood in a heated phase of the game or maybe was not thinking clearly when he chose to disrespect the game in such a way.
One also hopes that this will remain a largely isolated incident.
Which is why stern action needs to be taken on the midfielder so as to nip in the bud a nasty trend that is common in bigger leagues abroad.
The A-League has its weaknesses but one of its main strengths is that it is essentially an honest league where the game is respected and played in the best spirit of sportsmanship and competition.
I'm not saying that some players will not try to break the rules occasionally to seek that little advantage over their opponents.
But trying to get an opponent sent off by deceiving the referee is just not on. It's the pits.
I would be very surprised if City coach John van't Schip does not have a quiet word with his gifted midfielder about his deplorable antics.
On a positive note, Fornaroli continued to boost his reputation as one of the A-League's finest imports with a superlative display.
The Uruguayan striker seems to be getting better and better.
Not only does he engage in general play and provide openings for his team-mates, he is an exquisite player whose close control due to his low centre of gravity makes him a most difficult opponent to handle.
He also has this knack of scoring jaw-dropping goals. He opened the scoring in the first half with a curling shot across goal that nestled in the far corner of the net and he nonchalantly converted a penalty with a cheeky 'Panenka'.
Of course, we know now that Fornaroli does not do tap-ins and his two outrageous efforts against Adelaide enhanced his growing reputation as arguably the most gifted striker to play in the A-League.
He's an extraordinary combination of Besart Berisha, Carlos Hernandez and a snake dancer rolled into one.