This could be explained with the example of cars parked in garage. Since the garage is secure, there is no need to secure the car.In this respect, very good security at an airport  and planes kept locked in hangars or attached to jetways that are secure and under constant surveillance takes care of  no locks on the door of the jet. 

As is the case in any accident victim, your primary concern should be giving prompt and competent medical attention. You should  attempt take any statement . If you can do help the victim to get in touch with his immediate family or friends.

(The best way to deal  is to  coordinate with the Airport authority's instructions or rules.)