Prevention is Best!
Our jib halyard got away once while raising the jib, but never again! From the jib halyard snap shackle eye, run a short length of dacron samson braid (about 1/4 inch diam), just long enough to reach the second hank down the jib. On the other end, splice in a solid stainless ring just large enough so you can stick the jib hank through. When you bend on the jib, after attaching the halyard, run the second hank through the ring and then clip onto the forestay. In effect, the luff of the jib acts as a retrieval line should the jib halyard become disconnected. It ain't pretty, but it works!