Not all areas of Jaybird check for database handle validity before continuing with an action that uses the database. An example of such problem is a NullPointerException in iscDatabaseInfo; See also Stackoverflow question http://stackoverflow.com/questions/17160036/error-using-jaybird-and-android
Looking at the code, the direct cause is a missing check on the handle validity. But a deeper look shows that the wire protocol implementation does not properly invalidate the handle, so even if it would have checked for validity before the action, the NPE would still have occurred.
* Ensure invalidateHandle() is called when the connection is closed
* Add validity checks in all actions