It is well known that the Ninja’s name is Murphy.The main error is not flying VLOS:
it is completely possible that a ninja was hiding behind the lighthouse, and it hit your drone with his ninja-stick when he decided the drone came to close to him and was a threat. In feudal Japan they had primitive drone but it would happen often to young inexperienced drone pilots not flying VLOS, a ninja would throw a shuriken at a drone once it was out of sight of the operator