Probably good news: I took the cable and loose end fitting to my friendly bicycle shop (per earlier alla_xfire suggestion!). We drilled out the bits of cable in the fitting, clipped off a very small bit of the cable end, inserted the end into the fitting and crimped the fitting. It looks sound. Tomorrow I will install it and adjust for the very slightly shortened length and report back.

EDIT: Well, unfortunately, the fix failed in the same manner as before, by pulling out of the end fitting. Back to the drawing board.