Cam, I am no expert in the effects of "pulling" aerial G forces, but I can tell you the potential effects of impact G forces and the potential types of head injury due to my racing experience.
It was thought only 30 years ago in auto racing that a 40 G impact was not survivable. But impact-absorbing materials such as carbon fibers and so forth, which were not even dreamt of in WWI, have magnified the potential for survival exponentially. When Emerson Fittipaldi had the accident that ended his career (in '98?), he sustained over 100 G's and lived to tell. The collapsable nature of WWI airplanes is remotely related to modern race cars in that sense, and many pilots survived crashes where the G forces alone would have killed them due to the wooden structure of their planes.
Re: head injuries... the angle of impact is critical in determining the effect of a head injury. Blunt force is not always necessary to cause severe problems. The brain floats in a fluid which is encased by the skull. In some cases with angular impacts, the skull is intact and may have only shown slight injury, but the G forces actually forced the brain to spin slightly inside the skull. This results in a severe brain trauma which is difficult to detect and would have been completely unknown in the days of Taylor and MvR.
Slowness to think, comas, dizziness, vertigo can result from the brain's movement inside the skull, all to varying degrees. A race car driver, and without doubt a pilot as well, will be unable to perform to full capacity until healing is complete. And complete healing on such an injury is very difficult to ascertain. This sort of an injury is more common in impact injuries, however, and I have no idea if a bullet would could cause the head to snap in the same manner and have the same effect. Any extremely rapid movement of the head - movement so rapid that it cannot be executed by any natural or deliberate means - can produce such an injury.
That covers only a very small portion of the possible injuries to Taylor and MvR, so someone else will have to help us with things like skull fragments in the brain, and other things more closely associated with bullet wounds.
There will never be concentration camps in America.
We'll call them something else.