I understand that it happens, if any foreigner does some wrong deed in other country, that will be all over media but citizen's stuff do not get hot on news.
But I guess this act was all unnecessary, that guy doen't need to show cruelty on the dog, if he feel so that his own dog was being bullied then catching up the stray dog in his act and scolding him would have been impactful but i guess Mervyn's act is not justified anyway.