SO,That's a mistake, right?

optix5.0 programming guide P.40 Table 6 – Scope search order for each type of program (from left to right)

Search order of ch,ah,iset,aabb,should be Program, GeometryInstance, Material(first 2)/Geometry(last 2) and Context. not Program GeometryInstance Geometry Context.

Wow, yes, that table is not correct. I’ll let our technical writer know.
The text later down explains when the Material is looked up, but it’s missing from that table.

It should still be the same as listed in the OptiX 4.1.1 Programming Guide.

Ray Generation: Program, Context
Exception: Program, Context
Closest Hit: Program, GeometryInstance, Material, Context
Any Hit: Program; GeometryInstance, Material, Context
Miss: Program, Context
Intersection: Program, GeometryInstance, Geometry, Context
Bounding Box: Program, GeometryInstance, Geometry, Context
Visit: Program, Node

The Program variable scoping table has been fixed inside the OptiX Programming Guide and the online OptiX documentation
http://raytracing-docs.nvidia.com/optix/index.html
already contains the correct table again here
http://raytracing-docs.nvidia.com/optix/guide/index.html#programs#4119