London strategist Carlo Ancelotti claims that the referee lacked the courage to award a "clear" penalty kick to the goal.
According to the Italian, Patrice Evra clearly brought down Ramires as the Champions League quarter-final match was approaching its end, but referee Alberto Udiano Mallenco did not see the foul. Manchester United won the match thanks to a lone goal by Wayne Rooney.
"It's not easy to award a penalty kick in the last minute," said Chelsea's coach. "You need to be a strong personality and have courage. Not all referees can boast about that."
After the match, Ancelotti approached Mallenco and, not hiding his anger, accused him.
"It was obvious to everyone. There is no doubt - it was a penalty," Ancelotti added. "Not only the referee but also his assistant were in a comfortable position and could see everything.
"I told him that it was a penalty and he should have blown the whistle. The referee did not respond."