Saab: Saab parking sensors, reversing sensors, vector sport

Question
A Saab 9-3 Vector Sport Tid (4 Door Saloon) (57 plate) reversed into me - whilst I was also reversing - in a carpark.  I was fully out of my space at the point of collision, and she was approx 1 metre out of her space.  Obviously my contention is that she started reversing when she shouldn't (ie I was already totally out into the thoroughfare).

However, she is stating that she first reversed out - then noticed me STARTING to reverse, so she stopped - put her handbrake on - put her gear in neutral and waited for me to finish (ie she waited for me to crash into her?!).

To strengthen her side of things, she is saying that IF she had actually still been reversing at the point of impact, her reversing sensors would have sounded, but she said they did not (because she says her gear was in neutral, and the car at rest).  She has two witness who were in the car and will testify that the sensors did not beep.

So my question is: would the sensors normally beep to identify a MOVING object (ie my car)?  Could it be that when she reversed out the metre that she did (this distance is shown in the photos I took), that the sensors would not have had time to beep?  At the time of the accident I felt I had done everything right, and that she had definitely caused the accident.  I'm a hugely careful driver (have never had an accident in my life).  But this is making me question myself.

I do not have sensors myself, so I have no real clue on how they work.  My only understanding of them is that they alert the driver to stationary objects.  But I don't if they work for moving objects.

Thanks in advance!

Answer
Lori:
 As my profile states, my hands on experience is limited to the earlier SAAB 900s and therefore does NOT include your vehicle. Thus I cannot give you a specific answer.
 I do not know whether the SAAB in question has a "reversing alarm" [to warn others], OR a "proximity sensor" which warns the driver when reversing that she is approaching an object. I suspect it is the latter...it is also logical that the proximity sensor would NOT have been engaged, except when in reverse gear...as she states.Thus it would NOT have beeped as your car was moving.
 It is clear that she erred when simply stopping whilst her vehicle was halfway out..to prove negligence in a legal sense, however may be difficult.
 In the US, the onus of responsibility is ALWAYS on the vehicle that is moving, {if the other is stationary} regardless of the obvious contributory negligence on her part.
 So you should not blame yourself.
         Hope this helps,
         Jerry