The game is over, this is the place where the official game record stops, and it gives the result B+7. Various sources on the net differ slightly and give B+6 or B+7 or B+8. Let us ask Gnugo.
$ gnugo --score estimate -l ko.sgf Black wins by 1.5 points
Not very accurate, but this is only an estimate. Ask for a more precise result.
$ gnugo --score finish -l ko.sgf 262 black (X) move N5 263 white (O) move F15 264 black (X) move D15 265 white (O) move N6 266 black (X) move F14 267 white (O) move E15 268 black (X) move F13 269 white (O) move N5 270 black (X) move T6 271 white (O) move T4 272 black (X) move A13 273 white (O) move A10 274 black (X) move M2 275 white (O) move O1 276 black (X) move M10 277 white (O) move N10 278 black (X) move N12 279 white (O) move Q14 280 black (X) move O10 281 white (O) move D10 282 black (X) move N8 283 white (O) move O8 284 black (X) move PASS 285 white (O) move PASS Black wins by 35.0 points Result from file: B+7.0 GNU Go result and result from file are different
Funny. Basically the only point to settle is the result of the ko at N5/N6. But W finds a ko threat that gives away 28 points, the entire chain at F12. Bad.
The docs tell us that --score aftermath is even better, but it gives precisely the same output in this case.