Dalglish was frustrated by the dismissal of Spearing and felt it changed the outcome of the game.
"He won the ball," the Scot told Sky Sports 1. "He probably upset the referee with his follow-through but it's not his fault there's somebody standing there.
"You see them sometimes get a red card, other times they get away with it. The problem everybody has is the level of interpretation - that's not consistent.
"I think we would have taken something if we'd been left with 11 men.
"I don't think we played as well as we have been but we did enough to come away with something but we haven't done it."