[...He's hit a sore spot. She isn't sure, one hundred percent, that it's him. But she so badly wants to believe it's him, that she refuses to contemplate any other option.

If the man before her is that imposter again, she would know. The voice would be different, the clothing would be off, there would be some kind of hint.]

You may speak to me that way. However, my master is different.

If you have a similar relationship with your Moriarty, you should understand.