With scores locked away at 1-1 and the besieged Sky Blues down to 10 men following the 68th-minute expulsion of veteran midfielder Nick Carle, tall centre-back Matt Jurman appeared to brush Reds debutant Anthony Costa from behind, just inside the box.
Referee Strebre Delovski immediately blew his whistle and awarded a dubious penalty to the home side, which Jake Barker-Daish duly rammed home in the 72nd minute to give United the edge.
Tiring of weekly 'groundhog day' referee controversies, Farina clearly felt it was one that got away but wouldn't be drawn into the debate for long as he may have in his earlier coaching days.
"You can't tell from the bench with the angle, but when you saw the replay, I thought it was a bit soft.
"It's groundhog day for every coach in the league.
"Every week there's something controversial ... to be honest, I'm tired of talking about it.
"You can't do anything about it, so there's no point talking about it and complaining.
"I don't want to waste time in press conferences talking about stuff you can't change.
"When I was a young coach coming in I would have been complaining about this and that, but you learn over time you cant do anything about it. Nothings' going to change."
Swimming against a surging tide, undermanned Sydney showed tremendous resolve to turn it around and equalise in the 82nd minute through substitute Corey Gameiro's header to steal a point.
Farina felt his side earned the right to clinch a point and possibly deserved even more such was their impressive midfield ball use early.
"I thought we were going very well up until we had the red card," Farina said.
"Then to cop the penalty straight after that, always makes it very hard with 10 men.
"But prior to that I thought we were well in the game and most probably in more control.
"We're 2-1 down with 10 men - I would have signed for a draw.
"If you'd said to me before the game that we'll go home with a point, I would have been happy."
Sydney captain Alessandro Del Piero has had his fair share of injury woes in his advancing years and exited Friday's game in the 77th minute to rapturous applause and a standing ovation, which the Italian maestro responded to by waving and clapping to the appreciative Adelaide crowd.
Farina confirmed there was nothing sinister in Del Piero being substituted out of the contest and that the marquee superstar pulled up fit.
"He's fine," Farina said.
"If you think the last 5-6 games, he's only played (between) 30 mins, 45 maximum.
"I was happy to get (roughly) 70 minutes out of him.
"I'm expecting he'll be fine for next week."