To millions of football fans watching Australia play the Netherlands in Brazil, it would have been a meaningless, barely noticeable gesture.
But for supporters of Hibernian, one of Edinburgh's two professional football clubs, it was an outrage.
Ryan McGowan, who set up that Tim Cahill goal in Australia's eventual 3-2 loss, was seen making a "5-1" gesure behind his back during the World Cup match. He extended all five fingers on his right hand, and the index finger of his left.
But what does it mean?
The gesture goes back to a 2012 Scottish Cup final between Hibernian (Hibs) and their arch nemesis Heart of Midlothian (Hearts) - McGowan's team until last year. Both teams were founded in Edinburgh in the 1870s and their rivalry is one of the oldest in the sport. Informally, their matches against each other are called the Edinburgh derby.
The teams have met only twice in Scottish Cup finals, in 1896 and 2012. Both clashes resulted in a Hearts victory; the latter was an infamous 5-1 thumping.
McGowan's gesture, out of place though it may have been, delighted Hearts fans.
The gesture was used by thousands of Hearts fans, and even celebrities, in the aftermath of the 2012 match, Scottish newspaper The Scotsman reported.
McGowan, who unexpectedly played in Brazil after Ivan Franjic suffered an injury, says his performance has improved significantly under Australian coach Ange Postecoglou.
So funny some Hibs fans raging at Ryan McGowan's 5-1 gesture! Fantastic wind-up....think he caught a few fishies!— Ronnie MacKay (@RonnieMacKay) June 19, 2014
Just seen Ryan McGowan do a cheeky wee 5-1, LOL!!!!!— Nicole (@_NicFerguson) June 18, 2014
No way was that Ryan McGowan doin 5-1 in the world cup against holland in the biggest game of his life.... what an absolute gimp— Rory Emslie (@RoryEmslie) June 18, 2014
Thought Ian murray was bad shaving a 7-0 in the back of his head. But Ryan McGowan in a work cup match doing a 5-1 what a sad sad laddie.— gordon stables (@Goggs_84) June 18, 2014