She needs to be "adamant" because that person was in the control group". He was supposed to not have it but she was certain he did and he got tested for it.
I have a red coin and a green coin. I hide the two coins behind my back and ask you to pick the red coin. You pick my left hand, revealing a red coin. You then tell me to reveal my right hand because it also has a red coin. Even though I told you I only have a red coin and a green coin.
I don't believe you. Why should I? I selected a red coin and a green coin and you had already guessed which hand held the red coin. You stand firm. You're absolutely certain my other hand contains a red coin. I open my right hand and reveal a red coin.
You wouldn't need to be "adamant" if you told me that my right hand held a green coin. I know it was a green coin - I placed it there!
She had to be "adamant" because everyone thought she was surely wrong. After all - that was one of the control members. They believed she was wrong. Turns out she was right.
I have a red coin and a green coin. I hide the two coins behind my back and ask you to pick the red coin. You pick my left hand, revealing a red coin. You then tell me to reveal my right hand because it also has a red coin. Even though I told you I only have a red coin and a green coin.
I don't believe you. Why should I? I selected a red coin and a green coin and you had already guessed which hand held the red coin. You stand firm. You're absolutely certain my other hand contains a red coin. I open my right hand and reveal a red coin.
You wouldn't need to be "adamant" if you told me that my right hand held a green coin. I know it was a green coin - I placed it there!
She had to be "adamant" because everyone thought she was surely wrong. After all - that was one of the control members. They believed she was wrong. Turns out she was right.