Well the dealer is fixing it but I dont know if they are submitting it as a warranty issue to kubota?
What would worry me is what happened in the past with the previous owner. Did he loose all the oil then trade it in ?? Maybe that was what Coyote was alluding to with the paper work suggestion he had. If it is a crack with no leak then I don't see a problem unless he tore open the filter which you have no way of knowing.