Yes, agreed -- for common behaviours, it's hard to think of anything but evo-psy. Hypothetically, there could some global environmental factor that influences behaviour -- think gay bomb -- but that's probably not very realistic.

The trouble with evo-psy is indeed how it's hard to distinguish between alternative hypotheses.

Regarding the BBC-article - I think it is more about the dog owners than the animals themselves. But of course, if the only 'evidence' for dog-guilt is the bias of their owners, the case gets very weak.