From Fifa laws of the game, p. 111:

A goalkeeper is considered to be in control of the ball:
• while the ball is between his hands or between his hand and any surface (e.g. ground, own body)
• while holding the ball in his outstretched open hand
• while in the act of bouncing it on the ground or tossing it into the air
When a goalkeeper has gained possession of the ball with his hands, he cannot be challenged by an opponent.

Additionally:
• It is an offence for a player to prevent a goalkeeper from releasing the ball from his hands
• A player must be penalised for playing in a dangerous manner if he kicks or attempts to kick the ball when the goalkeeper is in the process of releasing it

http://www.fifa.com/mm/document/affederation/federation/lotg_en_55753.pdf

Saunders probably deserved a straight red for retaliation and raising his arm to the player's head...

...but c'mon.