Can a cracked (outlet) radiator cause a spun bearing(in the dealers words also grenaded)?

So the car started acting funny and was misfiring, all there was a service engine soon light and eventually it died....i took it into the dealer and they checked on it, and said it was seized, they said they could pull the pan and check the bottom of the engine...i denied, but the dealer sent there own engineers to check out and found out it was a spun bearing and told me it would be about 19,000 for a new engine. I denied for an engine and took it somewhere for a used one. But the place I took it to said my radiator was cracked and I needed a new one ($600) so I said yes because it might be coveted under a sulev warranty....got it back. Took it to the dealer and now trying to get the money back for the radiator...and I asked them if they saw that the radiator was cracked and the I believe manager said that the engine was grenaded and it had nothing to do with it....BUT how else can it have grenaded?