The Air Ambulance was in one night to our base. I was in the area but not all that close to him (not that it seems to make any difference). It was late at night in this small town so very quite. Up with my Firehouse strobes I knew the pilot could see me. He alerted the ground crew that a drone was in the area. I heard him start up his engine and started moving quickly back to home point. Finally got the first warning of aircraft in area now back home. I was down to 53 feet when he passed where home point was. Found out later they had even sent one of the officers out to find me and could not. All info is recorded on AirData and I had even sent a pix to the FAA (which they appreciated) along with the Trust certificate and drone registration. If this would have been during the day I doubt that I would have even been seen. I told the FAA I broke no rules and all clearance was given to the helicopter. My son (107) said of the night he pilot could not see how far away I was and would not have known I was one of the good guys. The file has been closed and the FAA is a little more particular on these emergency flights. On one side I was wrong but on the other side I did nothing wrong. Discussion?