First, let me be clear that I really empathize with you, as the experience must have been very scary. That being said, you have still not told us what the "warranty service inspection" four months ago included.
Truthfully, I don't know of any automotive inspection that could predict catastrophic failure of a master cylinder four months later. When a mechanic "checks the brakes" (assuming that this procedure was done 4 months ago), it simply means that he inspects the condition of the brake pads and rotors and checks the level of the brake fluid. If he is really thorough, he might also look closely for leaks in the hydraulic system. But, four months later, virtually any component can suffer catastrophic failure.
Also, I don't understand the reference to "My warranty miles are still valid at 58,700 though the 6 year deadline has now passed". Which warranty? If you are referring to the Powertrain Warranty, even if the 6 year limit had not been reached, brakes are not covered by a Powertrain Warranty. The master cylinder would have been covered by the Bumper-to-Bumper Warranty, but that warranty probably expired on the basis of elapsed time somewhere in 2004--if not before then.
You might want to read the actual wording of the various warranties on your car, as I think that you don't necessarily have a full understanding of what is covered by which warranty--even though the warranty issue is a moot point after all this time.
Unless you can provide us with a more compelling reason for either the dealership or Ford Motor Company to be responsible for this incident, I have to say that you are the unfortunate victim of catastrophic failure, and by its very nature, that is not predictable.