The result confirmed QPR's relegation.
Redknapp said: “He was only laughing because a lad who played for them (Daniel Carrico) came up and spoke to him when he came off.
“He wasn’t laughing about getting relegated. You can put a camera on anyone and see them laughing or talking — to start throwing that one at the boy is completely out of order.
“I don’t think he has done anything wrong. He wasn’t laughing about drawing or getting relegated, that’s for sure.”