Hamilton boss Billy Reid claims a harsh offside decision cost his side a point in the 1-0 defeat to Rangers.
But the effort was flagged by assistant referee Steven Craven and the Scottish champions held on to increase their lead at the top of the table to 13 points as Hamilton returned to New Douglas Park empty-handed.
"I've not seen it on the monitor and I don't have to," said Reid.
"At the time, I thought Joel Thomas could have been on an offside position but I saw with my own eyes James McArthur coming from well deep into the box.
"The ball is in the net and I was celebrating. I didn't have any doubt that it was a goal. They are telling me it was three yards onside so we've got to be disappointed."
Asked if he approached referee Stevie O'Reilly after the game, the Accies boss added: "I spoke to him and said I thought it was onside but the referee has a hard decision to make.
"He's got to call these decisions and sometimes they get it wrong and sometimes they get it right. He's called this one wrong."
"I was relieved, you always are," he said.
"While not being at our best today, we were through on the goalie three or four times and missed them all. We could have had a level of comfort so there was a little bit of relief there when the goal was disallowed."
The victory was far from convincing and Smith says fatigue is now playing a part as his battle-weary players head for the finish line.
He said: "I don't think it was nerves as such. Hamilton are always an awkward team to play against and there is a little bit of tiredness in our team, there is no doubt about that.
"There's got to be an appreciation of the fact. We have a smaller group of players and we've had a fair number of matches since the turn of the year.
"We have played 21 games since January and, with not being able to change the team around a lot, there is a level of fatigue there.
"At this stage of the season, I would hope people would understand there is a little bit of that involved."