Someone help me. I even have a perfect example of how disqualification is executed in a scene. Here is the link:

https://www.youtube.com/watch?v=dlFnNcWu6c0

@ 12:51, She says something and then the man says something that is interpreted as disqualification. Can somebody please explain this to me WHY when he said "No" after her remark, that can be seen as disqualification?