Who was doing what to whom?

Two men are in court accused of causing distress to a dolphin by swimming in the sea with it. They had been drinking and were messing about, but that's not really the point, is it? How does anybody know what the dolphin thought about it or how it felt? At least one witness for the defence has made the pretty obvious point that the sea is the dolphin's habitat, and that if it was disturbed by what the men were doing, it could and would have simply swum away. Somewhat reminiscent of the boy who barked back at a dog (see post dated 30/4/07) and just as daft. Once again, a waste of tax-payers' money.