The clinical significance of this memory pattern is not simply that she cannot describe the crash. It also means that her recovery — the surgeries, the early rehabilitation, the conversations with doctors and family, the gradual physical return — took place in a period for which she has no independent memory. She was active during that period; she was interacting with people; she was presumably processing information at some level. But the consolidation of those experiences into retrievable long-term memories was disrupted by the injury, and so that period of her recovery is as blank to her as the crash itself.
For the purposes of her later public role, this meant that she was always, in some sense, an observer of her own recovery — someone who knew what had been done to her body from the medical records and the accounts of the people who were present, not from her own memory of experiencing it. She was reconstructing her own history in a way that most people never have to, building a coherent narrative of what had happened to her from external sources rather than from internal recollection.
The result, paradoxically, may have been a kind of psychological stability that she might not have achieved if she had full memory of the event. She had not experienced the terror of the explosion and the fall because she had been either unconscious or in a physiological state that precluded the formation of memories. She did not carry traumatic memories of the crash itself. What she carried was the knowledge of the crash, which is a different kind of weight — significant and real, but not the kind that produces the flashbacks and intrusive recollections of post-traumatic stress in its most severe forms.