does anyone know of cases of aggressive dog behavior where it was proven that there was an outside influence?

yes i agree, its a fact that no breed of dog will attack without a reason. now they might attack if they have been provoked,were hurt or are in pain,being protective,scared or fear….etc

i've seen where people have said, a dog attacked a child….now dont these people think there might, just might be a reason? children dont know how to respect an animal,so they like to pull on tails,lay on them, and sometimes it hurts them and they cant say 'hey stop' and the parents are to busy doing something else or think its 'cute' untill the dog has had enough and bites,then the dog gets put down because the child was hurting and he couldnt say anything.
its so sad. this is a pretty good site for parents and pet owners to check out http://www.safekidssafedogs.com/Why_Dogs_Bite/why_dogs_bite.html
and here i found a paragraph to back up what i said in the beginning *"People should keep in mind that dog biting is based on behavior, in which certain environmental and social variables trigger the behavior. Hence, experts contend that there is no breed of dog that will attack somebody without any reason at all. This means that 99.9% of all dogs will not attack anyone as long as there are no viable reasons that will trigger the attack."