I bet the instructor that signed him off for his instrument flight test, and the examiner that passed him, are sweating bullets right now...
Why?
I think of it as a night and instrument rating as being tools in your piloting toolbox. But the fact that you have a tool may not confer upon a pilot the freedom to use it unwisely. How many of us were taught to use a hammer? How many of us then hit our thumb?
Both the instructor and the examiner are duty bound to not only assess the candidate's ability to use the tool, but also evaluate/mentor the candidate's judgement in how and when to use it. It's a moral responsibility of senior pilots to do something to mentor new pilots toward safe flying. Not only instructors, but also examiners. Certainly some if my wisest mentoring has come from an examiner during a ride.
Early in our piloting career (or right away for some), we graduate to a more useful tool - a four seat airplane. Having two more seats behind you does not always mean that you can fill them, that's the trained skill that sometimes it's not appropriate to use the tool you have - you're full of fuel, and it's a hot day, you can't fill those two seats...
Many times when training a new pilot to floats or skis, I spend as much briefing and in flight time mentoring
where to land, as how. This new tool, with added capability can lure a new pilot into all kinds of trouble. Similarly the designation of "instrument rated" can lure a pilot to think that they have it figured - but they still have to fly the plane! So I also teach that before you allow an ATC (or passenger) request to distract you, be very certain that you are flying the plane, and during the time you will be distracted by the request, the plane will not wander out of your control. I'm okay either tell ATC I cannot comply right now, or even "missing" the communication first time to assure safe control of the plane. 'Talk about people sweating bullets, how about the controller? That person would completely prefer that their request had be ignored or missed, rather than being the final factor in a fatal crash....