In the same way, to get my guard's job I explained how I dealt with being first on the scene to a crash on a motorway having pulled over when it happened in front of me, including things like protecting the scene with my own vehicle (parking it a little way back with hazards on and engine off), giving accurate information to the emergency services, protecting myself by wearing a hi vis coat I kept in the car with a first aid box that was useful, and indeed when to give up control of the situation and stay out of the way when the professionals arrived until I was required to give a statement to a police officer. It's all about acting responsibly with due regard to safety, procedures, and knowing when to acquiesce to a senior person and start following directions rather than giving them.