Seriously, you can drive a car over solar panels and they don't shatter, so this goes to show the amount of force an arrow generates.
The reason it has shattered is it looks as though it's struck perfectly in the crease between the glass and the frame. A true one in a million shot.
If this does happen to you, please let us know and we will replace it for you. We will also go to the police at the same time, cause why the hell is someone shooting an arrow in a residential area!