Commercial Truck Warranty Not Honored

2017 Freightliner driven bobtail 3332 miles from Tennessee (TN) to Oregon (OR) when it decided to throttle high on it's own. It was towed to authorized repair facility. They looked at the engine and truck computer reports. Said that the truck over revved and caused damage. Again, I questioned why it over revved but no answer. The warranty dept received the 33 page computer report, repair estimate and pictures. The warranty dept only sent me 8 pages plus a few pictures of damage. I questioned again why did it over rev but he wouldn't say. Their first offer was to ship the replacement parts to OR from TN but I would have to pay the $4452 labor costs. I have a 5 yr/500k mile warranty (100% parts/labor). I asked for him for the full report but he said any further info I needed to get from OR. Days later I received the full report from OR but warranty called before I could view them. When I said I believe mechanical error he said first offer removed, bring truck to TN at my cost $10k tow