Hate to hear about your problems at Ford.
I was a FoMoCo tech for 10 yeras, a shop foreman and even got to sit behind a desk for awhile before I got sick of Ford.
Anytime a vehicle came in for a base engine concern (crank/bearing/piston scuff/lock up) the first thing we did was pull the pan and inspect, then we got the service records, either from the dealership computer or the customers own oil change receipts. Woe to the customer who didn't have the proper documentation.
We turned down a lot of engine warranty repairs because of improper service intervals, especially on 4.6s with clogged oil pickup screens. Ford sets a recommended service interval, it is the customer's responsibility to adhere to that schedule in order to maintain warranty coverage. Maybe I am missing something, but Ford bears no responsibility in this situation as the customer failed to maintain proper service/maintenance on the vehicle.
Did the dealer do something shady by throwing away the engine oil, maybe. Did you get a conflicting report from the dealership as to the specifics of the situation, yes. By the time a tech relays the diag through the service writer/shop foreman and service manager, stories get screwed up. Does this shift the maintenance neglect to the dealer or FoMoCo? No.
Grab the 1-800# from the dealer and give FoMoCo a call, sometimes they will work with you. I cannot believe the dealer would have had a meeting with a district rep without you, that is not right. You, the customer, should have been present to tell your side of the story.