FlyChicaga
Vintage Restoration
Not sure if the crew used this button or not (an inside source tells me they did not, but I'll wait for the facts). However, this explains this system on the A320 through A380 series of aircraft.
http://www.flightglobal.com/blogs/flightblogger/2009/01/the-airbus-ditching-button.html
http://www.flightglobal.com/blogs/flightblogger/2009/01/the-airbus-ditching-button.html