Gillingham striker Danny Kedwell's twice-taken penalty left Port Vale boss Micky Adams furious as his side had to settle for a point.
Marc Richards put Vale ahead with a typical poacher's finish after 33 minutes but, when Rob Taylor felled Frank Nouble, Kedwell put his second spot-kick away after Stuart Tomlinson was ruled to have come off his line in saving the first effort.
"It was a fair result. Neither side did enough to warrant three points. But, having said that, we're disappointed because a disputed, twice-taken penalty has cost us three points," said Adams.
"The linesman said he was not on his line. However, I think if there is a penalty, the referee should ensure the goalkeeper is on his line and if he's not, he should tell them. I'm disappointed with the decision.
"At the time of the penalty, we looked reasonably comfortable. There weren't too many scares and we looked like we could hang on for three points.
"The formation they employed stifled us somewhat, so we changed ours to combat them. It was hard-earned point and we'll look forward to our next game on Friday night."