North End manager Simon Grayson was not impressed with official Christopher Kavanagh.
Grayson said: "The referee said to me at the end if he's got it wrong he will apologise. Well that's no good to us now!
"I understand it's a tough role to do, but that's a clear penalty there in the last minute.
"Jermaine wouldn't go down if he's got an opportunity like that. It's cost us from getting anything out the game.
"It was 100 per cent a penalty. Jermaine is wrong side of him, Hanley has kicked his backside and put him on the deck.
"We didn't get the breaks with the opportunity for two penalties. You get those breaks when you're at the top of the division."
Hanley had been a late replacement for defender DeAndre Yedlin, who appeared to be hit by an object thrown from the crowd.
Grayson added: "You don't like to see anything like that in any football match.
"Hopefully we can deal with it in the manner it deserves to be dealt with."