What has to be remembered here is, it is not simply by virtue of being a JW and refusing blood that these patients fared well. They were obviously given some very good medical care by trained professionals, and great precautions were taken to minimize blood loss. In the absence of the kind of resources used in these scenarios, the JW who refuses blood might well not fare nearly so well.
In other words, there's nothing magical happening here. You can't claim it's the result of obedience to Jehovah, because it's not. It's the result of good medical care that takes their personal beliefs into consideration and devises smart ways to work around them and still give the patient the best care.
Let's also remember that a JW going to medical school would be considered as seeking glory for himself...unless he gets called upon for the privilege of serving at Bethel, I suppose...