Like the author I immediately concluded he was in a car accident with a bull and that the bull was dead. It's like a 6 word story:
http://www.sixwordstories.net
>Thank God my son was fine, but the comment about the dead bull intrigued me. We didn't own a bull. Where was he? How did the bull die? And why was he telling me about it?
>Then he said, "The car is damaged but operable." All right. He had gotten into some type of accident, the car wasn't a total loss, and there was a dead bull (still a great puzzle).
But, thinking back now if I were to arrive at the scene and not have known about the bull beforehand that'd be quite a shock, so I think I've changed my mind on this one!