The centre-back powered a header into the net shortly after half-time with Hibs a goal down but the goal was ruled out with Martin Boyle either taking a touch or at the very least, interfering with play.
Speaking afterwards Ross said the Australian internationalist’s opinion had differed from his own.
"He said he didn't touch it, I thought he did. I thought that at the time and I thought he did watching it back, but he's adamant he didn't,” the Easter Road boss explained.
"Irrespective of that, I still think [St Mirren goalkeeper] Jak Alnwick had a good case. I don't think he would have got to the header but he probably had a case that Boyle was in his way if he tried to reach the header.
"It's a split-second decision from Martin. He knows if he doesn't get involved it goes straight in but I've got no argument with the decision."
Ross also insisted the equaliser was a learning curve for 19-year-old left-back Josh Doig, who may have been culpable for Joe Shaughnessy snatching a point for the Buddies late on.
"I think generally his defensive play has been pretty good; I would actually say this season he's probably not been as effective in the final third as he was last season,” Ross said, when asked if the youngster was partly at fault for the goal.
"It's something we're encouraging him to do [be more effective in attack]. It sometimes happens in your second season.
"Defensively, generally, he's pretty sound but I think he knows that body shape aspect of it and that awareness to smell danger in that part of the game.
"When a centre-half makes a run all the way forward, it does disrupt what you see defensively as Shaughnessy obviously comes a long way but you have to sniff out the danger in that regard.
"At his age it's all learning and today's another one for him to learn from."