The nurse's concern was not unfounded.
Could an intern who just arrived at this department immediately perform clinical procedures? Moreover, this isn't a typical clinical procedure.
In surgery, tasks like writing medical records and dealing with paperwork, as long as they don't involve invasive medical procedures on the human body, are generally more casually assigned by teachers to students. Even if something goes wrong, it's not life-threatening.
In internal medicine, procedures involving endoscopic equipment are among the few invasive medical operations performed within the department, and they are critical skills that greatly test an internist's abilities. Most internal medicine doctors find such procedures challenging, let alone medical students.
