The scratched Halo 3 Limited Edition packs are aparently only an issue in the US, since the company that produced the discs didn't fit a small piece of foam inside the boxes.
We can confirm that the Halo 3 Limited Edition in the Asia Pacific region has this foam inlay and it prevents the disc from coming off the spindle during transit.
We've opened up an NTSC-J version of the Limited Edition in Taiwan and we can verify that the foam insert is in place.
It's a simple but effective way of preventing the disc from getting scratched and if you've seen this in other regions, please let us know and will update this post.
Reg Hardware has a YouTube clip from Aussie Gamer of the foam insert here