Redknapp's side can duly feel hard done by after they fought hard for 70 minutes following Bobby Zamora's reckless red card early in the game.
Loic Remy then looked to have won the game for Rangers with a glorious strike after 84 minutes before Shaun Maloney's cruel free-kick stole a point for the Latics.
Speaking after the game Redknapp said: "We didn't deserve that, we deserved to win. We played with 10 men for nearly the whole game. It was a fantastic performance from every player and for them to lose is criminal. What have they [Wigan] done? They've kept the ball, passed it in front of us, but how many saves has our keeper had to make? Hardly any. My players are very low, as am I.
"If we had come off with three points with 10 men it would have given us a massive boost, a massive lift, and you'd have thought we could still win four games. But now it is going to be very hard [to stay up]."
The result leaves Q.P.R. and Reading somewhat isolated and two wins away from safety at the foot of the table. The Latics meanwhile are in the bottom three on goal difference from Sunderland who lost at Chelsea.