[inportb]

the NeXT case was also not made of pure magnesium

[joezydeco]

Okay, what else was in it? And let's leave things like decals and paint off the list.

[inportb]

  > magnesium alloy which is specially designed to be difficult to ignite

The story doesn't say what else was in it, but feel free to support the claim that the box was made of pure Mg and not an alloy, modulo things such as decals and paint.