Coventry boss Aidy Boothroyd believed the key decisions from referee Pat Miller went against his side in their 2-0 defeat at Crystal Palace.
The Eagles took the lead through Darren Ambrose after Miller penalised Gary McSheffrey for a backpass.
"There is a ball bouncing and you hit it as hard as you can against him or go into a tackle. He hasn't got it in him to hit a backpass with his right foot from there," said Boothroyd.
Boothroyd felt it was harsh to award a penalty for the second goal from Ambrose, when Richard Wood fouled Palace striker James Vaughan.
"I have the hindsight of video. At the time I didn't think it was a backpass and I definitely didn't think it was a penalty," added Boothroyd.
"The contact was outside the area and Vaughan has gone to ground. He was the most surprised person in the ground when it was given a penalty. But rather than complaining we should look at ourselves, we let the decisions affect us and didn't respond in the right manner."