Frank Nouble went down under the challenge of Stephen McLaughlin and Clough said: “I thought it was a very, very poor decision.
“Very rarely do you see a penalty given when the person who has gone down doesn't even appeal.
“He was getting up to play the next ball, and the one next to him was as well.
“When the referee has got two bodies in front of him I am not sure how he can give it from 20-25 yards. It was an astonishing decision really.
“We should have been out of sight. But when you have only got a minute and a half to go and the ball is slung in your box you have to get our and get a bit more pressure on the ball.
“But nobody is making him do anything rash. Macca has gone for the header. He was slightly wrong side, but the lad has just gone down and does not appeal for a penalty.”
On the game overall, he said.“I thought we were very good at times tonight. I thought we controlled the game for long periods and created numerous opportunities.
“Nathan Bishop has had little to do and we have several chances to put the game to bed. That's the frustrating part. The penalty on top just caps it off.
“Sometimes you'll see it through at 1-0. But we didn't do anything wrong.”
He added: “It is still a good point for us. It was the last minute and everyone is a little bit down when we've been on top and should have won.
“But it's seven points out of a nine and an away point – that's never bad. “But we should have won it and it is two dropped with chances created and the late penalty.
“We probably created more tonight than we have in the two home games and played some lovely football tonight. Third game in that was very encouraging.”