The match was one to forget for the visitors as they also had Ryan Lowe dismissed after he launched an elbow at Macclesfield skipper Sean Hessey under the nose of the referee.
Knill said: "I'm disappointed, we simply didn't turn up. We gave away two poor goals and weren't about to convert our chances at the other end.
"I thought the referee had a poor game and I personally didn't see the elbow incident and I don't know who else did but I'm not blaming the referee, he certainly didn't cost us the game.
"We're fortunate in that when we've had a blip other teams have had a blip as well and we're still in third spot, but we now need to dig in and show what we are made of. Fortunately, I believe we've got some quality in this side and that it will shine through."