I can,t judge a dog that I,v not seen but any dog with the right training,after bonding with a human they trust, can be encouraged to attack and hold or kill if possible almost any animal found in the UK . I would,nt be to quick to blame the dog.
Thats not true.
classic that,some dogs dont do certain quarry end of,no matter how much bonding you do ,you could superglue it to you back ,talking kindly to it for weeks it still wont do some species,its in thier or it aint.