Here, around time 14:30, you can see the bottom bolt. Just as important, you can see the shock bottom has a piece that extends into the hole as well and fits snugly. The bolt is primarily providing a clamping force, and the shock itself carries the veritcal loads. If the bolt is torqued correctly at installation, it should "never" fail in service.
http://youtu.be/qESVvEfn7oA