After giving Staron a Divine Intervention scroll, if you lie to Galsu Merith (the ordinator outside Tel Mothrivra) that he has escaped, the quest "Gone to Ground" gets removed from your journal. But then, if you speak to her about "Staron" again, she will tell you to give him a scroll of Almsivi Intervention instead, and your journal will be updated with a new quest stage. (The quest doesn't get added back to your journal, since you already completed it.) It doesn't matter if you've already spoken to Staron at Cephalod Keep to recieve your 200 Gold reward. This also doesn't stop you from speaking to Staron to recieve your reward after this bug occurs.