What I expected to happen was...:
for the launcher to quit with command-q, the menu bar quit command, or the quit shortcut in dock

What actually happened was...:
the launcher window closed, but the application is still open and can be still be switched to from the dock or command-tab. the only way to get it to close is to force quit from the menu bar, command-option-esc, or activity monitor. if activity monitor isn't used to force quit the launcher, the launcher helper will sometimes (re)open. after quitting the helper, the helper will sometimes continue to reopen until it is force quit and sometimes it will still reopen, in which case the correct process need to be force quit from activity monitor.

Steps to Reproduce:
1. Open the launcher

2. Try quitting the launcher, the window will close, but the app won't quit

3. Try force quitting the launcher, the app should quit, but the launcher helper may (re)open

4. If the launcher helper opens, try quitting it, it should quit and reopen

5. If it reopens, try force quitting it, it should stay closed

6. If it doesn't stay closed, go into activity monitor, select one of the processes with a blank name, and click the info button in the top left. if the parent process field says launchd (1), force quit the currently selected process. if not, click the parent process link until the field does say launchd (1) and force quit the process that has that for the field.

7. If it still doesn't stay closed, then your only hope is to try different combinations of quitting and force quitting methods.

NOTE: This may be a Mac only bug.