EMT Impersonating a Volunteer Fireman

I need help with this and any information would be great.  I am the Medical Officer on a Volunteer fire dept in Indiana.  Here is my problem.  We have received an application from an individual in our town who has interest of being on the department, however, the routes and actions of this young individual have put alot of doubt in the minds of my fellow firefighters about adding him as a member.  This young man is a EMT-B with the local EMS service, but in turn also tells people that he is a fireman with our department (which he is not). He put on his application for employment at the EMS service that he was on our department (which he is not) and there wasnt even anything done about lieing on his application.  My biggest fear....here we go....what is the liability of our department if he shows up to a scene before my fireman do?  Whether it is to a fire or medical run.  Which he self dispatches himself with a pager he bought off of the internet!!!!  Second concern, Since he in an EMT-B, and most of my fireman are just First Responders, how does that fare on a medical run if this individual shows up first?  Would there be abandonment issues?  Even though he was never techinically paged because he is not on our department.  Do my first responders ask him to leave the scene?  PLEASE HELP ME TO UNDERSTAND THE LEGAL ISSUES TO THIS ONE. Keep in mind that this is in Indiana.  Thank you in advance.