The answer is... BOTH.
I agree, it can be both....
I was talking to a friend of mine that took his dog to a dog park. A women walks in with a still intact male pit bull and the dog got away from her and started go after another man and ended up attacking his dog who was defending his owner....long story short the man got arrested because he was trying to defend himself with a pocket knife and the idiot owner of the pit accidently got a cut on her arm.....she called police because this guy had a knife......
In this case the the owner was the problem.....
“The answer is... BOTH. “
Agreed.