somethings seems very very odd about this. I don't understand first off hwo that much water could be in that engine, and if it was water ingestion that would have to be sucked through ALL cylinders to have that much water in it, or as others have said a coolant jacket been leaking while it was parked which makes more sense to me. your story doesn't line up. If thsi truck sat for a month water ingestion or not im almost positive all the water would have went past the rings and been sitting in the oil pan long before start up. Yes it would ahve caused a catstrophic failued but i don't think it would have been like this. Something was seriously done wrong here. Also they never contacted your warranty. I work for a warranty company and before they ever drop the pan or anything they contact the warranty and an inspector normally comes out and verifies everything before ANY teardown is completed. Pop those valve covers and check it out. somewhere along the lines i feel you are getting ganked.