He didn't say "Wipe out humanity", he said "destroy the world". I'd say a global thermonuclear conflict would do enough damage to call the world destroyed, even if humanity wasn't utterly and irrevocably annihilated.
If I smashed your phone against a wall, you'd say I'd destroyed it, even if it could in principle be repaired.
This is actually not that relevant. The only question is whether humanity could survive a Nuclear Winter...
He didn't say "Wipe out humanity", he said "destroy the world". I'd say a global thermonuclear conflict would do enough damage to call the world destroyed, even if humanity wasn't utterly and irrevocably annihilated.
If I smashed your phone against a wall, you'd say I'd destroyed it, even if it could in principle be repaired.