How do you know a person is addicted to propofol?

First. Propofol is a controlled substance that cannot even be prescribed. It must be obtained from an inpatient pharmacy directly to the department using it. Therefor the only way for someone to get access to it outside of a hospital is theft. For short in-patient use addiction is not possible.
Rare. It is rare for a person to be addicted to Propofol because of the nature of the medication.