Well, there was this medical student during a dissection class. He was so focused on finding a particular nerve that he accidentally poked his finger with the scalpel. He immediately panicked thinking he might have cut something important and started yelling for help. But it was just a minor cut and everyone had a good laugh about it later. Also, in a clinical skills exam, a student was supposed to examine a patient's abdomen. He was so nervous that he started from the wrong side and when the examiner pointed it out, he got all flustered and mixed up the rest of the steps, which was really funny to watch.
I remember a story about a medical student on a hospital rotation. He was asked to help a patient get into a wheelchair. He pushed the wheelchair right up to the bed, but when the patient tried to transfer, he realized he had forgotten to put the brakes on. The wheelchair started rolling away and the patient had to grab onto the bedrail to keep from falling. The student was mortified, but it was a really humorous moment for everyone else.