Dougie Freedman criticised referee Stephen Martin after Kike's second-half strike condemned Bolton to a 2-1 loss at home to Middlesbrough.
Boro had trailed after Seb Hines took down Craig Davies in the box to give away a penalty, which Davies converted emphatically.
But former Middlesbrough defender David Wheater was adjudged to have handled the ball in the box, which saw Grant Leadbitter equalise before Kike scored the winner.
Trotters boss Freedman though, thought that Hines should have been sent off after Bolton won their penalty, a decision which he believed would have changed the game.
Freedman said: "The decision was a game changer. It's as simple as that.
"Those who know me know I don't like to have a go at referees but I've got to stand up for my team and say that simple rules tell you that when you've got a player through on goal and he's taken down and there's no defender it's a penalty.
"It's just a shocking decision.
"If we go one goal up and they're down to 10 men then it gives us a chance of winning the game.
"We then gave them a present just before half time and then in the second half we gave it a right good go and gave it our all.
"But the brutal truth is, if you don't take your opportunities when they come your way and you don't concentrate on defending, you're not going to win games of football.
"Right now we cannot afford to give teams gifts and I think that's what we gave them to let them back in the game. "
Middlesbrough boss Aitor Karanka praised his side and singled out Kike after the Spanish striker scored his third goal in three games.
Karanka said: "Kike is very important for the team but I said the same thing after our first game at home to Birmingham, today the most important thing was the performance of the team.
"Without the work of all the lads it would have been impossible for him to score that goal.
"He's very important and the other lads know that when we work and create a chance, he's going to be there and he's going to score. We have to now keep going in the same way and keep working.
"It's the same for Kike. He's only been here one month and he has to keep working to improve every day because we know how difficult this competition is."
Boro lost 1-0 to Leeds at the weekend and Karanka was delighted that his side could bounce back with a win.
He added: "It's very important for me because when we play as a team with that spirit and that fight we can work and get to the top."