With the Bannsiders leading 1-0 going into the second half thanks to a Lyndon Kane strike the game was turned on its head as the hosts drew level.
Joe Gormley came off the bench to equalise, but replays suggested the ball struck the striker's arm before going in.
Jamie McDonagh, who crossed for Gormley's leveller, then fired the Reds in front before the visitors were were left angered again when Matthew Shevlin was clipped in the penalty area, but it was he who was punished by referee Lee Tavinder who booked him for simulation.
The result not only ended Coleraine's Irish Cup hopes but also a potential financial windfall from European qualification much to Kearney's frustration.
“How the linesman and referee can’t see that is beyond me,” he said.
“Let’s be honest, that has the makings of a quarter of a million or half a million pound decision.
“That’s the way I look at it, that’s the cold harsh reality of where we’re at and I’m the person that has to deal with it. On nights like this, it is inexcusable.
“I don’t care what you say. Depending on who you draw (in Europe) it’s potentially a half a million pound decision that he’s made. Simple as that.”
“To be honest I think Joe is worried he’s going to collide with the post and he is possibly trying to put the breaks on.
“The biggest thing for me is how far his arm is outstretched when the ball hits him. His arm is away from his body and that’s the part for me that’s unmissable.
“I can also tell by our players’ reaction. Sadly again, in big moments in big games in big seasons, we are talking about the wrong people (officials).”
Coleraine pushed for an equaliser late on and thought they had a penalty when Christopher Gallagher tussled with Shevlin, but Kearney was left feeling aggrieved again as it was his player who was punished.
“It was a penalty twice over, but the referee believes he has got that decision right,” claimed Kearney.
“You get a big read by people’s reaction and it’s just really hard to take.
“I thought we were exceptional and I couldn’t speak in the changing room after the game because I can’t criticise or be hard on our levels.
“Lyndon scored a really good goal and I thought we were outstanding. How we have come out of that game with nothing over 90 minutes, I don’t know.”