'Normally' defect detection is done with a static camera mount. The reason is quite easy: optical conditions do not vary, illumination is static and well-controlled as well.
Where I could imagine an application or a robot-arm mounted camera: optical inspection of cavities (where the standard approach does not apply):
Insert the camera into the cavity.
Rotate the camera to inspect eg. surface for surface quality resp. defects.
Requires quite some degrees of freedom from the arm. And an elaborate illumination system. But may come useful.