Unusual pinging issue (2005 Ford three valve V10)

I vote for the Knock Sensor. It's job it to detect the possibility of a knock going to happen, and computer will retard the timing to prevent a knock.
Under normal operation when the gas in the cylinder is ignited, the rapid expansion of the ignition, pushes the cylinder down. When a knock occurs, it is like hitting the cylinder down with a hammer, and it can blow a hole in the top of piston.