Throwing is still fucked up.

[Erik]

Clark Clarkson throws the backpack.
The steel-reinforced glass window was hit by the backpack.
The grille was hit by the backpack.

Throwing things into other things causes it to hit both things on the tile.

Clark Clarkson throws the backpack.
The steel-reinforced glass window was hit by the backpack.
The steel-reinforced glass window was hit by the backpack.

Or it just so happens to hit the same thing twice.