Liverpool manager Brendan Rodgers insisted the best team lost and blamed mistakes by referee Mark Halsey for contributing to their first defeat to Manchester United at Anfield since 2007.
Rodgers took issue with the sending-off of Jonjo Shelvey, the penalty that Robin Van Persie converted to win the game 2-1 and Halsey's decision not to award Liverpool a spot-kick when Luis Suarez was felled in the second half.
"We are bitterly disappointed with the result, I thought the best team lost," he said. "Of what we could control I thought the players and performance level was outstanding, what we couldn't control were decisions by the referee."
He added: "If Shelvey gets sent off for having both feet off the ground then Evans has to get sent off for that as well if you watch the replays.
"Jonjo is coming in from the side, it is a tackle the player has to go for and one the United player has to go for but the Liverpool player can't get sent off and the United one stay on the field.
"I thought it was very harsh and that was how it was throughout the game as a number of poor decisions went against us. The penalty was never a penalty. Johnson has made a fantastic recovery back in and I have no idea why Valencia goes down.
"Up the other end Suarez gets a toe on the ball, gets contact, goes down and doesn't get the penalty."
Sir Alex Ferguson almost agreed with Rodgers in his assessment of the match, although not over the United penalty.
"I thought we were poor. Over the last four years we have allowed the (Anfield) crowd to get at us a little bit," he added. "They gave fantastic support to their team and they dominated. We played better in the second half but it was against 10 men and Paul Scholes, Michael Carrick and Ryan Giggs' experience got us through.
"No doubts about the penalty though, it was reckless."