Rochdale boss John Coleman said after the 2-2 draw that the sending-off of Port Vale's Sam Morsy threw his side a lifeline.
Midfielder Morsy was shown a straight red card for a high and late challenge on Jason Kennedy in the 66th minute after two goals by Tom Pope had put Vale in charge.
Referee Andy Woolmer was booed from the field by irate Vale fans after the visitors had drawn level thanks to late strikes from Bobby Grant and Andrew Tutte.
Coleman said: "I can understand the Vale fans being frustrated, but in the cold light of day it was an outrageous challenge and the lad got what he deserved.
"There is no place in the game for challenges like that and unfortunately for Vale and Micky (Adams, Valiants boss), it cost them the game.
"It ended up being an eventful game but we had talked about keeping Vale quiet and we did for the first 20 minutes. It was drab until then and the atmosphere was like a library."