I think I read somewhere that even falling onto your head a distance of less than 3 feet can cause brain swelling and fracture.
Yes, certainly a shocking tragedy. From what little I have read, she didn't seem to have actually hit her head on the ground, which makes the lethal outcome of her seemingly harmless fall on the bunny slope unusual.
Another point that is important to keep in mind is that you could feel totally fine after a head injury. You don't have to be knocked unconscious or see stars to suffer a potentially lethal head injury. When there is bleeding or swelling involved, it could take hours before the bleeding or swelling progresses to the point that any symptoms appear.
Richardson probably felt completely fine at first--"Yeah, I fell down, ha ha!" Which would make it completely understandable that the responding ambulance was told that they weren't needed. Only after some time had passed and the blood from her epidural hematoma collected enough to really start pressing on her brain did she feel any effects, like a headache. If you suspect someone might have a head injury but shows no symptoms, it's still probably a good idea to check on the person periodically for at least 12 hours, even if they're sleeping. Wake the person to check on their condition and mental status. Explain to them to report any symptoms like headaches, dizziness, blurred vision, nausea, etc. so someone can take them to the ER to get checked out. Actually, that's one of the ironic things about brain injury--if you go to the ER right after the injury, there might not be anything to find because not enough swelling or bleeding has occurred yet.
This is a whole 'nother topic, but perhaps the Richardson tragedy might raise more awareness of another potentially big problem out there. There are probably a lot of service members coming home, or who have come home, with brain injuries recently who don't know that they are injured and that the consequences are not only physical. These wars, in particular, have exposed soldiers to a lot of concussive forces from land mines, IED's, and other explosives. Even if there isn't a scratch on you, the force of the explosion can literally rattle the brain inside your skull and cause a brain injury. Even mild injuries can permanently affect your ability to concentrate, your emotional control, alter your personality, affect your memory--basically hinder your ability to work, maintain personal relationships, and function as a contributing member of society.
Unfortunately, we don't hear much about it at all in the media since mild brain injuries are still a little understood area of medicine. And there is also probably a lot of psychological trauma in these vets, too, which makes it difficult for people to figure out why someone came home from the sandbox as a different person, can't hold a job, was always loving but just argues with me now, etc. Did this person have psychological problems, or is it actually the consequence of a brain injury? Add the effects of alcohol and substance abuse that too many vets with "issues" resort to on top of that and the true underlying reasons for these problems is hard to see.