Everton manager Roberto Martinez was left angered with what he believed was a deliberate elbow from Papiss Cisse on Seamus Coleman in his side's 3-2 defeat to Newcastle United.
The incident happened while Everton were leading 1-0 in the first half, but Craig Pawson failed to spot the contact in the box, and Cisse would go on to score as Newcastle won a thrilling match at St James' Park.
"The view is clearly that this is unacceptable, that an action like that goes unpunished," Martinez told Sky Sports News. "You get a situation where everyone is fighting for their position, all in control, and it's a clear elbow to try and hurt someone.
"Those are not actions we want to see on a football pitch, and the referee should have seen it."
Everton will look to end a run of three successive losses when they meet Hull City on New Year's Day.