I noticed this same problem running the sample code on my Nexus 4 (Android 4.4.4). I found that if I commented out the following line of code in the ActivityDetectionRemover continueRemoveUpdates() method, it fixed the problem:
mCurrentIntent.cancel();
Sorry, I don't yet have a good explanation as to why canceling the PendingIntent causes this issue.
UPDATE: I also commented out the cancel in the MainActivity onStopUpdates() method:
mDetectionRequester.getRequestPendingIntent().cancel();
Which is effectively doing the same thing as the first line above.