There are many factors/reasons involved in bites…protective of the dog’s home/family, being cornered…but in my estimate is the third option…highly prey/protective oriented working dogs can be incredibly effective. And that can be anything from rat terriers to German Shepards. But that same thing that makes them effective also has a fault in processing their bred instincts and go/no go from time to time. True handlers around the dog all the time know the dog, but the average owner does not. PD/mil working dogs are some of the most well selected but they still bite handlers and cops/soldiers.

Dogs have little to no color vision…that is basically blurry past about 30 ft…and running and “screeching” are also triggers. Plus dogs pack up so if one gets confidence or a wild hair, other dogs instinctively join in. There is also a scale of dog bite reasoning and severity.

Wikipedia has a page about fatal dog attacks and certain breeds stand out…as well as the fact people under about 15 and over 60 have a disparate chance of death due to physical ability to resist.

I’ve had two neighbors with great bigger dogs when the owners are around but also fall into instinct mode with anything from a squirrel to a person and BOLT randomly at any of them. They aren’t the typical breeds, but something in some dogs is a wild card and can be very bad in a very small amount of situations.