This situation is compounded by my brother's family's rationalizing this biting and placing the burden of prevention on the family's accommodating behavior and not on modifying that of the dog. They seem to have devised a plan that relies on avoiding another biting event through changing their interaction with the dog. The vet simply said that he thought this approach would work for their family, and didn't appear to mention anything about this troubling information about Springer aggression, etc. In light of the information on your site, this seems like insufficient council. On behalf of my family, I thank you in advance for your assistance.
Springers appear to be much more likely to suddenly bite than the average breed.
Some people feel that this is just an extreme example of dominance aggression that occurs in a few breeds including springers. Other behaviorists feel that there is a difference in this behavior since many of the incidences have a specific pattern in which the dog really appears to be in an altered state of consciousness at the time of attacks and that there may be a genetic factor influencing a specific syndrome that is different than dominance aggression. Therefore, there are a lot of approaches to the problem based on whose theory of the problem is believed and then what approaches have worked in the past for the person treating the problem. By far the best thing for your brother's family to do, if it is possible in your area, is to consult with a board certified veterinary behaviorist or a certified animal behaviorist. There are very few of these people in the country and that makes it difficult to obtain really expert help in many areas of the country.