"Football is about emotions and all that, you score goals and concede them, you are up and down in 90 minutes and you talk about decisions made by the referee, but it's a part of the game," BBC Sport quotes Laudrup as saying.
"What makes me frustrated is when you see our disallowed goal. We are not talking about a decision, we are talking about the rules of football.
"When the ball comes back not off one player, but two, it cannot be offside. It's like giving offside from a throw-in. It's frustrating."
The defeat leaves Swansea ninth in the table with 40 points from 29 matches.