> This year one of my students claimed to have done a user experience test with 30+ people, all of which came in person to his house during a period of 4 days.

Is it possible that maybe he thrown a big party (or a series of parties) and asked the folks there to try his stuff? Not sure what is the length and depth of the usability test in question, but if it is a short questionnaire that might work? But I see where your suspicion is coming from.