"How was it that I knew? I already told you the answer to that.” Vandread answered.

When Vandread told him about it, the sentinel's muddled state of mind caused him to work up the energy to think about it. However, much to his dismay, he was unable to recall the exact moment when Vandread had told him about it. 

The Sentinel then clenched his fist, showing his anger at the fact that he was rendered incapable of even standing as a result of Vandread's success in locating his weak points. And the result of Vandread's attack on him was that he became crippled because he was unable to get up on his feet.

The sentinel eventually responded, "I don't remember that you said anything about it." 

“Fuh. I