It's not misinformation. A bats wing and a whales flippers contain all the bones and joints in a hand but you don't say that those animals have hands. The foot to leg joint in elephants does not function the same as the ankle joint does in other four legged animals due to the way the heel structure is prevented from touching the ground. Yes, there is a joint there and yes it contains the same bones you find in feet but it doesn't do what those same bones do for other animals.