StephaneLamy:
After M6 N6 N7 M7 O6 L6 L5 M6 M8 L7 K8 N8 O7 L8 R4 Q5 O8 Q6, L9 is winning and seems the only move, but is marked "incorrect"

posetcay:
Removed the branch where opponent plays M7 at L6 and added refutation to the variation where O8 is played at L9.