dkup: It is marked correct but the eye on the border can be falsified.
caranthir: Can you give an exact sequencce for your argument. In the correct variation, an eye (at G18, upper right coordinates) can be removed by playing at F18, but after that, eyes are immediately regained because of oshitsubushi. If opponent on the other hand first removes an outside liberty, then we have time to make two explicit eyes.
@caranthir he means that playing O3 in the end instead of M1 is also marked as Correct which is wrong