I think I misunderstood your problem. The lilian didn't come off the tip, it just became lodged in the second section, right? Did you take off the butt cap? Ususally the tip section is slightly longer than the second section in order to avoid having that happen. If the second section rode up, you might be able to push the tip back thru from the bottom. Once you do have it exposed, a larger knot, as suggested, should prevent reoccurrance.