Aberdeen boss Derek McInnes felt a sense of injustice at going a man down against Rangers until a half-time talk with referee John Beaton.
Attacker Ryan Hedges was dismissed in the 26th minute with the game tied at 0-0 for accidentally clipping the heels of Alfredo Morelos as the Colombian striker readied to shoot.
Initially McInnes thought the red card, which transformed the complexion of a game the Reds would lose 2-1 to the league leaders, was harsh.
Until Beaton explained the letter of the law during the break.
McInnes said: “My feelings at the time were that Ryan did everything he could not to make the challenge.
“He didn’t want to run into the back of Morelos and as a consequence knew more or less he would get his shot away.
“You can see that with his body movement.
“It seems a really unfair outcome. You would think if Ryan did everything he could not to make contact that would have some bearing on the decision.
“However, John Beaton explained it to me at half-time and said he had nowhere to go with it.
“He said he knew it was accidental, but because it wasn’t a genuine attempt it had to be a red card. Once he explained it you would have to say it is the right decision based on the laws.
“The irony is that if Ryan had actually made an attempt, swiped him down and not won the ball, he would have got a yellow card and we would have continued with 11 men.”
Rangers captain James Tavernier missed the resultant spot-kick.
However, goals either side of half time from Morelos put Rangers two in front. Rangers had conceded just five goals in 22 Premiership games this season, so any notion of mounting a sustained comeback looked slim.
McInnes said many other teams would have folded and praised his side for their fighting spirit.
McInnes said: “The second goal was a real blow for us and a lot of teams could’ve really folded then.
“It was an uphill task at 1-0. An even bigger uphill task at 2-0.
“I said to the staff at half-time, we are going to find out a lot about our players in the second half. It becomes more about being a good footballer in these situations.
“If you are 2-0 down against a team at the top of the league and more or less a half to go, you have to take real responsibility.
“You have to show bags of spirit, organisation and a mature performance. We had that.”
Aberdeen hit back through a superb strike from substitute Matty Kennedy just moments after his introduction.
McInnes said: “The goal was a real shot in the arm for us.
“It gave us the belief that we would have one more opportunity in the game to get something, but unfortunately it wasn’t.
“We lost the game, but can still take a lot of encouragement from the level of performance and application from the players.
“We just came up short, but it wasn’t through any lack of effort.”
There were calls from Rangers players for Aberdeen to be reduced to nine men shortly before half time when Curtis Main went in aggressively on Borna Barisic and was yellow carded.
Main was substituted for Shay Logan just three minutes later.
McInnes said: “I know it was a robust challenge, but it was a yellow card every day of the week, I have seen it again.
“Curtis did not hurt the boy. He (Barisic) was running about fine.
“A lot of people were losing their marbles a wee bit about that, but the right decision was made.”