Your suggestion has prompted me to read up on "fractography," a subject of which I'm unfamiliar (and with which I will only be slightly less unfamiliar after this post).
There's a type of glass damage called "Wallner lines," and it seems to fit. Here's the definition, as found
here:
Wallner lines are faint, striation-like markings formed by the interaction of stress waves reflected from
physical boundaries with the advancing crack front.
This
FBI fact sheet on glass forensics talks about them as well.
C.W., you've led me to consider an obvious cause of the scratches - stress on the glass from shattering - that we had not considered. Due to its simplicity, it would be in my opinion a cause favorable to Occam. Once again, the Forum helps light the way!
As you can see, we were far too unsure of ourselves to mention this topic in our paper. I can see now that erring on the side of caution before consulting with this group was a wise move.
Joe Cerniglia ~ TIGHAR #3078ECR