It is poor form, but in this case, it was probably unwise for a law student to wear a Rolex. Regardless, it probably does not convey the right message. The way that I look at it--what you wear is just about the ONLY thing that you can control. And you know what? In a 20-30 minutes interview, the interviewer NEEDS to make snap impressions. There is not enough time to ferret out the details. So judge away, as far as I am concerned.
This is why I interview in the nude. I don't need anyone making rash decisions on my ensemble choices.