The Silkmen opened the scoring through Hamza Bencherif but Stanley looked to be heading for defeat after Andrew Procter and a penalty from Phil Edwards put them ahead.
Yet Macclesfield substitute Vinny Mukendi rescued a point in stoppage time and Coleman said: "We put on an extra man at the back at the end to man-mark the giants they had thrown on but they lost him and it was a lapse of concentration.
"We should have won the game when they were down to 10 men, in fact we should have won it before that unless they've changed the rules I've no idea why our goal was disallowed in the first half.
"If we had scored that I'm sure we would have gone on to win comfortably. It's a mark of how far we've come as a team but they were so delighted at the end they thought they got a real scalp in getting a point at home to Accrington.
"Now I know how Alex Ferguson must feel. We've been on a good run but now we've got a long time to stew before the next game. We are healthily in the play-off places but as far as automatic promotion goes we need other teams to slip-up and we can't afford to slip-up ourselves."