The Reds took an early two-goal lead but were pegged back by their local rivals, who managed to see out the game 2-2 at Goodison Park.
The clash should have resulted in Liverpool taking all three points but striker Luis Suarez was wrongly ruled offside after finding the back of net in the final seconds of the match.
"Credit to Everton and the way they fought back but we feel disappointed we didn't get the three points as we had a goal dubiously disallowed right at the end which would have given us the victory," Allen told the club's official website.
"It was mixed emotions for us at the end. It was a great feeling for a split second because we thought we had won the game, but it wasn't meant to be. Hopefully next time we will get the decision."