2010 Toyota Camry Warranty dispute

I have a 201o Camry with a V6, last week the car left me stranded on the side of the road had it towed to the nearest Toyota dealership. They called the next business day to inform me the engine block had a hole in it. I asked how could that have happened and the service guy said they didn't know yet. They wanted all of my oil change service records. They had records up to 35,000 mile because I had taken it to them for the free oil changes. I took them the recorded after 35,000 miles up to 51,000 miles. They contacted Toyota and the service guy said they now need to tear down the engine because either a component failed or I ran the car into a deep water and sucked water in through the intake and damaged the engine. I informed the service guy, it wasn't raining when the car failed. I was driving 60 mph down the highway, the car made a loud bam noise and I pulled over off the road. When I tried to re-start the car all it did was go clunk, did not turn over. I checked the oil and the dipstick was on full. When the wrecker arrived and when he was pulling it on the rollback that is when the oil started pouring out of the engine. At that time I didn't know it was from a hole in the block so there is no way it was from me running it into water. The service guy said then I don't have anything to worry about then. Today they call after they tore down the engine and claim they aren't going to warranty the engine repairs because they say at some point the engine ran low on oil. That is a complete lie, this car has never ran low on oil, I check it every week and have never had to add top off oil in between oil changes. The oil has been changed every 5000 miles per Toyota service requirements. Now they say if I had of had the oil changed at their service department the whole time this wouldn't be an issue. I asked what if I had changed the oil and filters myself, I suppose you wouldn't honor that as well. He said yes basically you would be in the same boat. My question is how can a new car with 56K miles on it, who has not been ran low on oil, and had oil changes have a rod thrown without any warning? There were not any abnormal engine noises prior to the failure, and as I stated earlier even after the failure the dipstick still showed full of oil. There wasn't any oil on the ground until the wrecker moved the car on the rollback. Now I am told I have to pay $10,000 for a new engine or move the car and pay them $1800 for tearing down the engine. I thought Toyota was better than this. I have owned many different makes of cars over the years and have never been treated like this before on a warranty issue.