Adams angered by tackle
A competitive local derby saw both sides claim a point after two goals in the space of three first-half minutes.
Richard Stearman opened the scoring for Leicester before Stern John's equaliser.
The visitors were reduced to ten men in the second-half when Patrick Kisnorbo was sent off for a foul on Andy Whing, one that angered Coventry boss Micky Adams.
He said: 'It was disgraceful. He deserved a straight red and anyone who tries to defend it has got it wrong.
'It was two-footed over the top of the ball. There was no attempt to play the ball at all and I was disappointed.
'It was a local derby and it was competitive and he was playing a blinder but he spoiled his afternoon.'
Leicester manager Rob Kelly did not disagree with the red card, but said: 'It was a bad tackle but mis-timed rather than malicious.
'I know Patrick Kisnorbo and he would never seek to deliberately hurt anyone - you could see that by his immediate reaction because he tried to help.
'But he's a good player and a good person who's already held his hands up and admitted he got it wrong.'