Coventry caretaker manager Andy Thorn refused to criticise Marlon King for the foul which gifted Derby a point in a 2-2 draw.
Aron Gunnarsson and King put the visitors 2-0 up five minutes before half-time, but Steve Davies pulled one back and Robbie Savage equalised from the penalty spot after King felled Jamie Ward.
Thorn said: "I don't want to dwell on it. We played some terrific stuff and even at 2-2 I said we are not settling for this, let's have a proper go even if we win 6-4.
"The attitude and application for 85 minutes was bang on but we had a five-minute sloppy spell and got punished. But we gave a great account of ourselves.
"Marlon scored a good goal and worked his socks off for the team, he just made a mistake."