Raise the Hammer

Ryan, whilst i'm glad to hear that your neighbour was not seriously injured, her example is as much evidence for one side of the debate as it is the other:
She presumably rode for years without a significant accident , and the first time she wore a helmet she crashed badly.
No one admits, or possibly is even aware that they make different choises when wearing a helment, but it's all subtle responses that happen due to subconsious risk-perception.

A similar "helmet saved his life the first time he wore it" story was in the local papers here a couple of years ago. It turned out the rider was taking the same route home from school he always has (without incident), but on this occasion he sped right through a stop sign thinking he could get through before a truck.
The author of that article jumped to the same conclusion you did, aparently not even considering what was different on that day that may have caused him to run the stop sign.

Certainly these could just be coincidences, but OTOH they could well explain why injury rates to cyclists are higher in countries where there is greater helmet use. Individual cases can't be used as an indication, only when larger numbers are looked at does the overall picture become more clear.
It seems that most riders have a "helment saved my/friends life story", yet the statistics clearly show there were never that many serious crashes before helmets were popular. Either the crashes would not have caused injury anyhow, or the crashes would not have happened in the first place.

here's a great site about bicycle safety http://www.bicyclinglife.com/SafetySkills/SafetyQuiz.htm
and another one with facts and figures on the subject of helmet safety:
http://www.cyclehelmets.org

So spread the word about cycling as the great safe and heathy sport it really is !