Steps to reproduce:
1. Open applet and java console
2. Open OS X Console.app
3. Focus applet or java console
4. Hit some buttons, you will so this in the Console.app:

06.06.14 11:09:02,553 java[98031]: java.lang.NullPointerException
at sun.awt.SunToolkit.getSystemEventQueueImplPP(SunToolkit.java:1081)
at sun.awt.SunToolkit.getSystemEventQueueImplPP(SunToolkit.java:1076)
at sun.awt.SunToolkit.getSystemEventQueueImpl(SunToolkit.java:1071)
at java.awt.Toolkit.getEventQueue(Toolkit.java:1734)
at java.awt.EventQueue.invokeLater(EventQueue.java:1251)
at sun.plugin2.main.client.MacOSXKeyHandler.notifyFlagsChangedFromNative(Unknown Source)

EventQueue.invokeLater should be change to something that explicitly sets the AppContext.