Brechin were stunned on Monday afternoon when they managed to give away a three goal lead to their visitors, eventually losing 5-3.
City had two players sent off, Max Kucheriavyi and Iain Davidson, with Davidson’s coming in the final seconds of the game.
Kucheriavyi saw red just before the break with Brechin 3-1 up and Kirk believes that proved to be a turning point.
He said: “The red card affected the game for us because I believe if we kept 11 players on the pitch in the second-half we’d have created chances.
"We worked hard but it’s down to decision making, when to dangle your leg at the edge of the box, when to clear your lines and when to put your foot through it.
"These things have cost us.
"It’s not the effort or the work-rate, it’s the decisions that cost us the goals.” The defeat leaves Brechin six-points from the top of the Highland League but, with plenty of games still to go, Kirk is hoping to see a response from his side.
"You have to remember these feelings and use them as motivation but we can’t feel sorry for ourselves because there’s a lot of the season left and a lot of points up for grabs,” he said.
"We have always been going in trying to win every game but now that becomes even more so.
"We have to pick ourselves up for a big game on Saturday at Formartine and that’s not going to be easy either.”