They are in an interview which is not a normal situation. The way they read the situation, the interviewer was laughing at them. It is normal and very very common to be oversensitive and misread things like that during an interview.
The interviewee is not your friend, he/she do not know your brand of humor or internal jokes. Additionally, he/she may have cultural differences.
You talked with someone an hour in an unbalanced stressful job related situation and you really think you know something about their personality? Behavioural researchers think that you can't know much. I wouldn't be so judgmental of people you've just met. You should be more aware of the limitations of the interview platform and stick to what you can deduce. (Which is not, that a person is toxic, because he/she felt laughed at)
