Freefall strictly speaking means 9.8m/s/s which, after 228 seconds, multiplies out to 5000mph. That's an order of magnitude more than Baumgartner's speed. Wikipedia explains:
"The example of a falling skydiver who has not yet deployed a parachute is not considered free fall from a physics perspective, since they experience a drag force which equals their weight once they have achieved terminal velocity (see below). However, the term "free fall skydiving" is commonly used to describe this case in everyday speech, and in the skydiving community."
Still, terminal velocity for a human at sea level is about 120mph which is 4.5 times slower than the quoted 536mph. Taking the square root gives an atmospheric pressure 2.1 times less than normal which translates to him popping the 'chute at about 25,000. Actually he had a pressure suit which would probably slow him down so it could have been higher than that.