First thing is to stop reacting emotionally to the jerk but rather rationally. Ask yourself why the jerk behaved the way he did. One could easily reason that it's not uncommon for the interviewer to talk down to an interviewee because they are looking for a job.

As such, the interviewer feels like they are in a position of power. This is why top tech companies often make the interviewee do a lot of work and go through the rigorous process of multiple interviews before getting hired. They feel like they can do that in their authority position. However, this doesn't make it right.

People who abuse their power shouldn't be in their authority position. An abuse of power is when they use their position to feel superior to others. It's likely the jerk has low self-esteem and was taking advantage of his position to feel superior to the candidate. Such people do not belong in authority positions. I would speak to your boss about his behavior and recommend the jerk not be the interviewer anymore for the reasons stated above.