Sounds very logical to me. 

I'd guess that even a golden retriever could be turned into a viscious animal if every time it seen a human it was shocked or mistreated in some other cruel manner. 

It's not a natural thing for cattle to attack humans.  I know some folks think it is, but it's not.  I've never heard of one case of any bovine killing a human for food.  There is no 'natural' instinct to attack humans.  Natural instinct is to move away if given the choice (if there were no pens or fences interfering in their movement).  Cattle are NOT natural predators of anything besides forage and grain. 

The only way that changes is how they were treated in the past by humans.  First this animal had to get over the fear of being close to humans (pretty easy with a historically domesticated animal), then it had to be mistreated by humans in some form or fashion.

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Very sad deal for the family of the deceased ...

... and for all the folks in the past who mistreated this animal to make him into the killer he was (cause they don't know any better).