In another perspective, these restrictions pertain to research quality. Each location, employee, or whatever is being tested is to be handled in the same manner by all evaluators-- regardless of evaluator status as employee or IC. These are simply the rules of research. If there were no controls, there would be at best a melange of apples, oranges, orangutans, fantasies, and whatever else an evaluator could express. As it is, the restrictions define the metrics of research, not the evaluators per se.
Nature does not hurry, yet everything is accomplished. - Lao-Tzu