It was part of the exercise. There was something on the list but not in the cupboard. I left them with specific instructions to ask if there was anything they couldn't find and to let me know when they were done. The first thing I asked once they said they were ready was "Did you find everything easily?"Did you forget to make all equipment available?
It is true that there is more to being a technician than eg. missing forceps but attention to detail is very important and so is willingness to ask questions when you're unsure.
In my opinion, personality and how someone reacts under pressure are more important than technical knowledge.