Players and coaches were present at the informal function the day after their dismal defeat to cross-town rivals the Sydney Swans, with the performance heavily criticised by caretaker coach Mark McVeigh.
The playing group have recently taken ownership for the 73-point loss, with McVeigh stating a number of players had 'checked out' of the season with a month remaining.
While tensions hadn't seemed to have sparked among the currently 16th-placed side, a verbal altercation between O'Halloran and Buchanan over a footballing matter is understood to have taken place in recent days.
According to reporter Tom Browne, the Giants are aware of an incident and have suggested there was no fracas despite the recent mail that was floated to Browne.
"This came across my desk yesterday a suggestion that at the post-game barbeque over the weekend there was a fracas and verbal disagreement between an assistant coach Buchanan and a player O'Halloran," Browne told Triple M.
"I put this to the Giants last night. They said there was nothing untoward, they've looked into it on an informal basis. There was certainly no fracas according to the Giants, and there was certainly no inappropriate verbal barbs, which is what was put to me.
"It's certainly a discussion point. This exchange of words amongst the Giants playing group this week, but just in terms of reporting both sides of the facts I put it to the Giants. They agree that there was some heated words between the assistant coach Buchanan and the player O'Halloran, think directed from the coach Buchanan.
"It involved football. I'm told there was nothing inappropriate said. They've been training together and coaching together with eachother this week. There's no ongoing issues.
"It came up on my radar yesterday, it was at the barbecue, some heated exchange of words over the weekend. The Giants have told me there's nothing more in it than that."
O'Halloran was among the Giants side that fell to the Swans on Saturday, collecting seven disposals and failing to boot a goal.
Ahead of their Round 21 bout with Essendon, McVeigh may look to swing the selection axe for the weekend ahead after noting only eight players deserved praise for their efforts against the Swans.
The Giants will confirm their 22-man for Saturday's clash with the Bombers at 6:20pm (AEDT).