Ti failure remains rare, but when it happens, it seems to come out of nowhere for no obvious reason. I guess the installation of the cable stop introduced some very slow-moving stress riser. Are you going to get it repaired? I don't know what I'd do in your situation, given the age of the frame, the likely cost of decent Ti repair and that sweet looking Croll in the wings. I have what I consider to be a lifetime Ti frame, with 21 years and ~100k miles in, but if it failed like yours did...it might be time for something with wider tire capability and disk brakes.....