This is very unfortunate, #422 R.I.P.
Still, I find it strange that the mirror would pop out, like you say it did. You see, the mirror is secured by several of retaining brackets, besides that it is made of flexible material, plastic. So it should withstand any bumps in the road and impacts from sides while in transit, even on its back with mirror weight 'backwards' (cabinet orientationwise). Provided that it was properly secured and mounted from start. Also, I would imagine that if, I say *if* there was a crack already in the plexi it could have been displaced slightly, and thus crumbled during impact.
Damn, now I remember that I had one whole mirror from my Starblade, I gave it away to a friend while cleaning out my storage! And then, as he was cleaning out his storange, about a year ago, he mentioned this mirror asking me if I'd like it back. Ofcourse I said no thanks! And now, when it is needed, it is no longer! Damned!
I'm so ... I have scattered my Starblade all over Sweden. The gun controller went to a guy named Jesper, and the mirror went to Patrik here nearby. But both the items are probably trashed by now. I blame myself.