Phil Brown believes his struggling Preston would have left Doncaster with three vital points had a second-half penalty decision gone in their favour.
Paul Hayes came off the bench to salvage a 1-1 draw for North End, who remain second bottom of the npower Championship, after Brian Stock opened the scoring for Rovers.
A frantic contest was still delicately poised at 0-0 when Preston forward Eddie Johnson broke clear of the home defence before going down under a challenge from James O'Connor.
Contact appeared minimal and referee Scott Mathieson was unmoved, although Brown later revealed that O'Connor told Preston striker Iain Hume he felt himself lucky to still be on the field after the incident.
"To not get the penalty was, for me, the pivotal moment of the game," said Brown. "It's the reason why we've only got one point and not got three.
"The lad who made the tackle said to Humey that he thought he was lucky still to be on the field of play, so how is that not a penalty? Unless he was pulled down why would Eddie not go round him and stick the ball in the back of the net?"