FWIW the materials (splice case and splices) are about $100 and the labor is somewhere near 1.5 hours to do this if you haven't stretched the cable too much. (YMMV).

None of us here could plead ignorance for not calling Miss Dig, or whoever you have in your state, but you just might pull it off.

Use a lot of "I didn't know" and "I never expected" etc.

It can't hurt.

Carl