Long-time lurker; first-time contributor.

At ORD last week, I had passed through the security checkpoint and was collecting my carryon bag when I noticed something that seemed out of place. The TSA clerk operating the X-ray machine at the checkpoint was able -- via either an open panel or some sort of large hatch that I could see from my position at the end of the belt -- to reach inside the X-ray machine and remove items for visual inspection.

To clarify: though bags and personal items passing through the machine remained physically and visually inaccessible to their owners, the clerk on the opposite side of the machine was able to remove them by an opening on his side of the covered portion of the belt. I wouldn't have noticed at all, except that he had actually reached inside the machine and pulled out a pair of boots to visually inspect their interiors. It seemed like a serious security issue ... the clerk could have removed items from bags, or even put foreign objects into them, without passengers being any the wiser.

Has anyone else seen this before? Is it SOP for TSA clerks to remove items from the covered part of the X-ray belt for visual inspection?