It happened to bounce close to Terry Butcher, startling the Inverness Caledonian Thistle manager, who turned round, glared and pointed menacingly at the offending section.
The spectators cheered, and Butcher turned his attention back to the match where his charges were menacing a Hibernian side devoid of the fight required to get back into the game. Butcher's vignette - and his now ritualistic post-match conducting of supporters in a series of orchestrated cheers - is demonstrative of the reciprocal bond between diehard fan and bullish manager.
His confidence permeates into a team of willing workers who have taken the SPFL Premiership by storm with their slick, passing play and keen eye for goal. They have, of course, had the luxury of being able to field an unchanged line-up in their opening eight league matches, of which they have lost only one.
Nevertheless, with a striker like Billy McKay - who has been in form for long enough that the term has lost its meaning - leading the line, their place atop the SPFL Premiership is fully merited. His two strikes, the first aided by the ineptitude of a Hibs' shaky defence and the second an unstoppable 25-yard bullet, once again underlined his capacity for scoring all manner of goals. Richie Foran it was who scored in between McKay's strikes, the Irishman too alert for everyone else in the area when Ben Greenhalgh's header came off the visitors' crossbar.
"We've made an unbelievable start to the season," said Gary Warren, who produced yet another exemplary display at centre-back for the home side. "Despite losing at Aberdeen last week and performing poorly in the League Cup-tie at Dundee. Against Hibs was more like it. We showed what we are all about again. Whenever we start well we seem to kick on and that's what happened. We were comfortable throughout because of our fitness and our attitude. We were quick out the blocks and showed what a good team we were.
"Billy is in great form. He scored a couple of great goals and could have maybe even scored a few more. The lads created so many chances that we went in at 3-0, but disappointed it wasn't four or five. That's the standard we set ourselves. The nice part is that's four clean sheets at home. It's not down to the back four, it is down to the whole team and it starts with Billy. He does brilliantly with his goals but he is also our first line of defence. He works so hard at chasing down defenders. "
There is much to be said also about the contribution of Foran, a player at the heart of this Inverness machine. With the stamina of a long distance runner, the Irishman protected his defenders and ensured none of the opposition midfielders were allowed to impose themselves on proceedings.
As for the visitors? Pat Fenlon will head back to Easter Road not only worried about the leakiness of his defence, but also the paucity of creative play and failure to convert scoring opportunities - of which there were only two - into goals.
Ben Williams, their goalkeeper, perhaps summed-up the Hibs performance best as he alluded to having too many players off form. "We let ourselves down," he said. "There were too many of us who weren't at the required tempo.
"It is one defeat in seven so its important not to get too carried away with it, but there are things we need to work on and this serves as a reminder to us all not to get too carried away with ourselves.
"This is still a learning curve and part of the rebuilding process. There were times in the game we played much better football than they did. But they are effective at what they do and at the end of the day they have the points on the board and that's what matters."
Many at the ground would wince at the element of delusion in that assessment. Hibernian have time, at least, in which to regroup and work on the many flaws on show before they next see action, against Partick Thistle at Firhill a week tonight.