Tony Pulis was disappointed after Stoke conceded a last-gasp penalty against Reading at the Madejski.
Michael Kightly scored on his Stoke debut after a howler from Reading keeper Adam Federici.
But the hosts improved after the introduction of Garath McCleary on 67 minutes and he was brought down by Dean Whitehead in the box late on to earn the spot-kick.
But referee Kevin Friend allowed the game to continue and fellow substitute Noel Hunt was denied by Asmir Begovic before the referee brought play back, awarding the penalty and showing Whitehead a deserved second yellow card.
Adam Le Fondre despatched the penalty to deny the Potters and Pulis afterwards wanted clarification of the situation.
Pulis told Sky Sports: "(I'm) disappointed obviously because of the lateness of their goal.
"And looking at it, it looks as though Deano has caught the lad but the referee has played on and the lad's had a shot, which Asmir's saved and then he's pulled it back and given a penalty so I'd like clarification of that rule - how long you wait because there was a couple of incidents first half with Crouchy where Peter was fouled and the ball dropped down and he played on.
"It went the one time to Matty (Etherington) in the air, the lad's challenged him and then taken the ball away.
"So just clarification of that rule, if it's a new rule or if it's not a new rule, or how long you're going to get until the referee pulls it back."
Regarding the game overall, he said: "It was difficult, the conditions, how hot it was today was really difficult and I thought the first 20 minutes we were very, very slow out of the blocks.
"But from that point until they got the penalty, I didn't think they created very much."