Every interactive Flex component has a "click" event that is triggered when the component is selected by the mouse. It quickly becomes an ingrained habit to add a click event to components you want users to select. This habit lead me into trouble with a List component.
The "click" event for a List occurs whenever any part of the List is selected. For example, selecting the up button of the scroll bar will cause the List component to emit a click event. This isn't the event you want to respond to if you are trying to detect when an item in the list is clicked. The actual event I needed was the "itemClick" event. It seems like a small thing but it made a big difference to how my small application worked.