The first thing i have to wonder, is he absolutely certain there wasn't a power outage when it happened? Typically, a bad connection doesn't just make or break cleanly without some other indication such as lights flickering etc. unless the fault is inside the breaker. First,i would remove the panel cover and look for loose or discolored connections, then try some resitance tests with the power off. If nothing shows up there plug in a large load such as a portable space heater and check amperage on that ckt. and look to see if the bedroom light is flickering.
Are you a liscensed electrician? If not then i suggest you consider calling one.
Zero
