Fellow builders --
My Tattoo has experienced two such failures. Both happened under strong winds. The first probably on a downwind reach when I heard a noise that I thought was something falling in the cabin. The second occurred a year later. On both, we kept sailing in strong winds unaware of the damage which was not noticed until Tattoo was recovered onto her trailer.
My first repair was inadequate and probably amounted only to cosmetics without strengthening the original construction. Inspection showed that the cleat along the forward underside edge of the cabin-roof failed (not the glue joint) -- probably because it was made of cheap pine. I also noticed that I hadn't wrapped the cabin-roof/bulkhead edge with fiberglass. I didn't try to replace the cleat with stronger wood, thinking that the fiberglass wrap (over the edge of the bulkhead/cabin roof interface) would sufficiently strengthen the joint. And I also thought the SS L-bracket (inside on the cabin-roof centerline) would add the necessary additional strength. Obviously, I was wrong! The repaired bulkhead was probably weaker than when originally installed. The L-bracket didn't add any strength -- it just bent. However, it may have limited the damage. The following photos show the damage and repair procedures.
In "replies" to my own posting I'll add further photos and comments.