Protecting Patient HIPAA

Suppose a doctor left his flash drive with the details of more than $700$ of his patients at University Hospital in his vehicle when he went to get it detailed. One of the car wash attendants was able to access the unencrypted material.

Identify one vulnerability for this scenario.

Identify one threat for this scenario.

Identify one possible control $($i$.$e$.,$ mitigation$)$ for this scenario.