I’ve worked lots of accidents, and glass on the inside as you experienced is not uncommon if the windshield sustains a great enough impact. I’ve seen impacts from bird strikes, crap falling off the back of tractor trailers (ie bricks, pipes, tools, etc…), large pieces of steel belted rubber from an exploding tire, etc…all do this. It’s common to see the driver/passenger(s) with glass on them if there’s any glass damaged from the accident.
And then you have things that are more criminal, like baseball bats, axes, and gunshots that will all cause spalling.
IMHO as scary as glass might be to get in your eyes, breathing in the glass “dust” is much worse because if it enters your lungs, there's no way to get it out. Glass in your eye can be bad, but most of the time, not rubbing and washing your eye(s) with water will get it out.
I suppose there could be a manufacturing/design defect but considering the size of the bullesye and radial rings, it appears that the glass did it’s job.