"I sensed that van Persie was offside on the first penalty. That was the key moment of the game," Pardew said after the game.
"It was the first crucial decision and it was a real triple whammy - van Persie was three yards offside, Sankofa didn't pull him back too much and then for him to be sent off was too much for the team to handle with the results we're having.
"We had four key players out so it was always going to be a tough call even with 11 men on the pitch, let alone with ten for an hour.
"If we had got even a draw tonight, we would have been whooping around in the dressing room.
"Darren Bent's injury is pivotal. We can not afford to lose a player of that calibre for too long.
"The next week will tell me how bad the injury is and I will have to work out where I go from there."