Your cousin may wish to bear in mind that interviews are not naturally "comfortable" experiences.
And in medicine sometimes they are supportive and helpful and sometimes they feel as though they are deliberately playing bad cop, or unresponsive listener to see how somebody would react.
The looking out of the window, apparently not listening etc, being grumpy, isn't a nice experience, but may be deliberate to test them. I have heard others say similar.
If I was applying for a job, and my interview didn't go well I wouldn't complain about the interview being inappropriate, unless it was inappropriate, ie, interviweres were racist, sexist, went against employment law. Big red flags only.
It's a matter for your cousin, but how do they know how they scored yet, and how do they know how others were treated? It may have been unpleasant but it doesn't mean it was unfair.