I think the dog in question probably needs euthanized, but I think its always good to get a professional opinion by going to a reputable behaviorist first.
Perhaps a better comparison for dog temperament would be my two dogs. They came from different areas/situations, but they are essentially the same working mix. The ratios are a little different, but essentially you can very easily tell they are the same working mix type when you see them or pics of them.
Lily I would consider sound and even bombproof. I would call her well bred despite not knowing her breeding. I know she could easily do what she was bred to do (distance mushing) and excell at it, however I don't have the inclination or time to seek that out, so we do other stuff. She has a very sound temperament and recovered from being smacked around and dumped to starve very quickly and easily. Her only lasting issue is that she's got an eating disorder from her days ont he street, which really is very easily managable.
Scout on the other hand I know was out of **** poor stock genetically speaking. Knowing some nitty gritty details of that situation and the aftermath she was born into... there were a LOT of dogs that should have been euthed for temperment. Instead they were mostly adopted out. I've seen no less than 10-15 back int he system in only the two years I've had Scout. Scout is almost 4... Some of these were euthed by the shelter that took them in, others adopted out again. This I know from a friend of mine who works at the shelter that did initial intake, she may chime in if she wants to. Specifically I remember her telling me about one pup born into the rescue after the hoarding bust who was adopted and returned for biting children in the home. And on good old fb, one of the dogs was returned by its adopters for repeatedly biting, but instead of being put down it gets to be warehoused in rescue its whole life. All the pictures on the web and otherwise of nervous dogs throwing out calming signals and uncomfortable body language...And yet the "rescuers" and owners are patting themselves on the back for a job well done.
Well let me tell you. I live with one of these dogs. She is one of the much better wired ones out of that bust. Her two previous owners were very nice people that exacerbated some already genetically present issues without meaning to or knowing any better. She wasn't abused, she wasn't unsocialized by most people's standards, in fact by most people's standards the first home did everything right. So why was she so f'ed up when I first met her that I literally had to crawl into her kennel and clip the leash on and pull her out to take her somewhere? She was put in situations where most dogs would bite in her second home, including an unsupervised 3 year old biting her! Most dogs fear response in defensive, whereas Scout's is to huddle down and wait it out. She has a phenominal bite threshold and its the main reason she is alive today. If at any point she had proved herself willing to bite people out of fear, I'm sorry but I would have humanely euthanized her. Its not fair for anything to live with that much fear. Some drugs work to a point, but honestly if they are hardwired for something.... I just feel letting them go is more fair to THEM. I think people forget a lot of the time that its more important to do whats right for the overall well being of the animal, while not forgetting to hold public safety at the fore as well.
It came down to me or the shelter for her. I took her because I knew she'd just get put down. Two years later and most people dont' notice she has any issues at all. IMO there is still a LOT of work to be done. And we still have days where I am upset as hell to have to see her live with that genetic anxiety that I can't fix. There are plateaus and backslides as part of the work toward making a better life for a dog like this. Thats normal, but its frustrating. Most people would give up. When I took her I was expecting an easy fix like with Lily. I wouldn't change my decision to take Scout for the world. I have learned far far more about dog behavior, genetics, training, and etc. than I otherwise would have. However, I don't really want another project after she's gone. Like ever. Maybe its a selfish waste of talent, but I'd rather get a nicely bred dog I can just enjoy. Maybe someday I'll work with people on their problem dogs or something.
So yes, I believe hardwiring does play heavily into temperament. And unfortunately you can't always fix what is broken.
Whats great about bulldogs is that the work they were selectively bred for meant that those guys had to be able to get in there and physically seperate the dog from whatever. For the most part, they were selectively bred to pretty much be the most trustworthy companion a human could ever have and excell at also being the most badass dog at what they were bred for at the same time.
Its too bad large chunks of GSD breeders have given more thought to looks than temperament and working ability. IMO a good shepherd SHOULD be an allround extraordinarily sound dog. The same could be said about nearly all the other breeds too.... Fun what happens when looks become more important than function!