I totally agree with Karen. that whistle probably startled him and he didn't know how to react. I hope your brother is okay and I sure hope it never happens again. and I don't think he should be pts just for an accident. It was an accident and accidents do happen and your mom shouldn't be so harsh on Rupert IMO anyways..and I would never ever punish my dogs just because of an accident. they do not know what they did wrong and therefore they shouldn't be punished for it.