rt/apps/toys/PickTest3D will fail occasionally with an NPE when using multitouch

     [java] Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
     [java] at picktest.PickTest3D$2.handle(PickTest3D.java:437)
     [java] at picktest.PickTest3D$2.handle(PickTest3D.java:410)
     [java] at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)

It is suspected that the app is at fault as it is changing out the picked Node in the event handler and an event is hitting either the new node before it is attached, or just after the old node is detached. The code is replicated at least twice.

This is only seen when using multiple fingers - in effect fuzz testing the app, as selection is usually done with one finger.