Actually, IME not so big a stretch as it appears.
I work in the animal medicine/welfare field and there are bucket loads of data that indicate people who perpetrate acts of violence against animals usually have a history, or will have one.
I'm hip to your reference to the bambi syndrome BUT, she did not swat a fly or even chop a snake in half with that shovel. She beat a young defenseless mammal to death. Before someone yells out "species elitist" let me 'splain.
Most humans of all demographics, even those with concrete firmly under their feet will, at the sight of a fawn, display or express some sort of concern/delight/empathy or other positive interest in the animal. Their initial reaction will not be to bludgeon it to death. I get paid to treat injured wildlife, deal with the people who find and or interefere with it, and when possible educate them. This event was not anywhere near normal.
This was not hunting nor nuisance control.
As for hardened hunters, most are also compassionate at least on some level when it comes to animals. It is the way of things. I hunt with gun bow and hawk. My fangs are as sharp as any on this list. But when the day comes that I feel nothing when game is brought down, that day I will hang up my weapons of war and turn the bird loose.
In regards to the highlighted above just a couple of thoughts.
Do hunters perpetrate acts of violence on animals?
She is 75 if she had a history I'm sure the media and her neighbors would have included that in their story.
This was not her initial reaction or first time encountering deer in her yard/garden. It has been an ongoing problem for her for nearly 10 years according to the article.
I would say it was most definitely nuisance control, at least to her. Deer ravaging her landscape for nearly a decade was probably a real nuisance.
From personal experience I can tell you that in areas of deer over population deer are most definitely considered a nuisance. They will mow down gardens, shrubs, fruit. etc with ease. I have seen and heard of farmers losing up to 25% - 30% of a crop to deer, that is some serious coin. If you live in an area with these kind of deer populations then you are probably already aware that your car insurance rates can be as much as 15% higher than other areas and even if you don't care about the insurance rate you just might care when you are driving that brand new "pearl" of a truck you finally bought into work early one morning and you put a doe through the radiator you might even view those deer a litttle different, maybe consider them a nuisance. Hopefully noone gets injured.
Truth be told here these do gooder neighbors love to watch the deer, it's probably a real novelty to them. They probably name them and feed them and tell all their friends how they can see deer right in their back yard. Oops they forgot to mention that their 20 acre neighborhood and surrounding roads and conveniences all used to be woodlots or farmland and all of those deer have nowhere to go now, but hey aren't they cute.
That last part is hypothetical of course, I can't really say "truth be told" with any degree of certainty but I'd be willing to bet it's not too far off.