Bale looked set for a torrid evening when he spurned two first-half chances.
The winger blazed over and fired at John Ruddy before the break and also had to endure taunts from the home fans, who took to calling him a "chimp" in an attempt to get under his skin.
The taunts may have helped spur his star man on, but Redknapp was sickened to hear the taunts.
He said: "That's disrespectful. What's that all about? It's just sick. Why do people say things like that? It's not on."