Bad bounce on the glass
I had this situation in a game. During the service, the ball bounced on the floor and then hit the point where the fence and the glass meet, probably a little more on the glass side. It sounded like it hit the glass only and not the fence at all. However, the ball exited with a very close weird angle, making it extremely difficult to return. I believe the glass or its assembly is defective in that spot.
Is there any rule about whether that’s a good point or a fault? We decided it hit the glass so it was good, but clearly unfair because the receiver couldn’t return it (and it happened twice).