I have a grid of titles inside of a panelset. When you select a title it will append a panel to display that titles detail information. If you double click the "ok" button on that grid it will append two detail panels.
as soon as the first click is received set a flag m.inProcess = true or something. In your init sub, set m.inProcess = false. In your onKeyEvent check if m.inProcess then return true so the click is ignored. When your thing finishes adding or later goes away you need to set m.inProcess back to false so you start listening for clicks on that screen / component again.