No legal reason.
You do not usually run from a wreck - speaking from experience. Car and aircraft.
You might want to work out any particular safety brief - but really, it is no different to taking someone for a ride in your car, should you crash it! (Except that the ANO requires you to give a safety brief before every flight whereas the Road Traffic Act doesn''t before every journey.)
For instance, you might want to tell them - I will probably be first out the aircraft so as I can go and get help. So you might feel you have been left on your own.
Whereas, the usual I say to someone with full mobility is: get out the aircraft, forget about me, and just get well away from it and get professional help from 999.