The Magpies were on top at the Stadium of Light until their captain was shown a red card following a challenge on Steven Fletcher in the penalty area just before the break.Adam Johnson converted the spot-kick to put Sunderland 1-0 ahead, before Sam Allardyce's side went on to cement a 3-0 victory due to goals from Billy Jones and Fletcher in the second half.
"In my understanding it has to be a clear goalscoring opportunity. I didn't think it was at all," Elliot told Setanta Sports.
"For a decision like that to lead to a sending off and a goal, it doesn't see fair."
Sunderland have moved above Newcastle into 18th place in the Premier League.