I recorded another session with the OpenEEG… this time with a proper signal as evidenced by the OpenEEG RAW channel. The audio plug-out triggered from the OpenEEG channel at 0118:
Eye Movements at 0118

And then from the halograph FM channel at 0333:

Heartbeat Spike at 0333

Lost signal with a false positive at 0411:

Bad signal at 0411

That should be enough for me to add a signal quality channel and avoid false positives.