The 2-1 defeat to West Brom at Loftus Road left Harry Redknapp's team bottom of the table.
Robert Green failed to stop a 30-yard drive from Chris Brunt in the first half and the goalkeeper's afternoon then took another turn for the worse when he dropped the ball into his own net to make it 2-0 to Albion.
Replays showed that West Brom forward Marc-Antoine Fortune clearly backed into Green, stopping the England goalkeeper from collecting the ball that had looped up in the air off Armand Traore, but Foy allowed the goal to stand.
Redknapp was furious at Foy's performance afterwards and Cisse, who scored the hosts' only goal, also hit out at the official's decision to allow Albion's second goal to stand.
"I've seen the video again and again and it was clearly a foul for their second goal," Cisse told QPR's website.
"He didn't attempt to play the ball. Rob couldn't do anything. It was a clear foul and it cost us dearly. We all feel sympathy for Rob. It wasn't his fault. There was nothing he could do. He was clearly fouled.
"Everyone in the stadium was waiting for the referee to award a foul. He didn't, and it's cost us points."