If you intentionally fire a weapon into the air you are committing a FELONY. If you accidentally discharge a weapon you will still be charged with a misdemeanor "illegal Discharge". If that accidental Discharge happened within a certain distance...
Sorry for your loss, had the same problem with auto take-off from slow moving ship,... Answer from Dji support was, Manual "Flight Environment Requirements"-7: DO NOT take off from moving objects such as cars and ships.