The Black Cats headed home from Anfield on Saturday evening adamant that they should have had a penalty and not entirely convinced the spot-kick from which Liverpool completed a 3-0 victory should have been awarded.
Whitehead said: "The penalty the ref gave was easy for him in front of the Kop.
"I don't know if Nyron got the ball cleanly, but it didn't look a clear penalty.
"The home side went up for it and that might have influenced the decision.
"We had a couple of shouts for a penalty and if they were Liverpool appeals, I think they would have been given.
"It is easy for the referee not to give the decision to an away side at Anfield.
"You just want consistency in the decisions because they are very big decisions for a club in our position.
"It's impossible to tell if it changed the outcome, but you look back on these things and feel hard done by."
Sunderland have not enjoyed the best of fortunes at the hands of referee Rob Styles so far this season.
It was he who awarded a penalty against Danny Higginbotham at Blackburn for handball on January 2, a game during which he also sent off Dwight Yorke, and he also dismissed Paul McShane at Arsenal earlier in the campaign.