Why is it surprising that college newspaper did it ?

It is lot more likely to be able to get to spend countless hours required than a large commercial publication for an investigative piece ?

Student journalists get paid far less if anything at all and will definitely be motivated in a story about their college and put in the extra hours than a professional journalist also easily tap into subject matter expertise right there in their college

Journalism quality is a primarily function of how motivated the journalist (and the publisher) is about the story, there is no shortage of talent in university like Stanford.