Sadaharu: After P1R1, playing O2 should be correct also theoretically. Even though it may not be the best move, from a tsumego point of view I don't think it should be considered wrong.
caranthir: Added. There's been similar tolerance in other problems of this collection.
After P1 R1, playing O2 should be correct also theoretically. Even though it may not be the best move, from a tsumego point of view I don't think it should be considered wrong.