Two goals from Fernando Torres and a goal from Raul Meireles secured the win for the visitors.
“I think we let them off the hook by trying to play offside after 30-odd minutes,” McCarthy said.
“We then got done by a wonder-strike which no-one is stopping – you could have put two goalkeepers in.
“The third one is incidental because the game was finished – two mistakes and a wonder strike.”
“We beat them when Roy was there. He is such a great guy and a top coach but it is Kenny Dalglish coming out of the stand,” he added.
“I think he is enjoying a support and a warmth Roy didn’t.
“He has garnered and nurtured that and they are on a better roll than they were because of it.”