While it was genuinely WRONG for him to shoot down your UAS, put yourself into his perspective.... some random DRONE is obviously tracking you to take your picture... it's not just sort of in your direction but changing positions and in every position pointed "seemingly" (although in this case more than seemingly) directly at you. If you saw a person intentionally taking pictures of you from the ground walking around your dock/deck/yard/home to get your picture from different angles would it also not alarm you?
In this day and age that could be considered a very threatening maneuver and he OVER-reacted in a hostile/protective manner. Yes he was at fault but you also shoulder your fair share for being rude and irresponsible/inconsiderate.
What happens if he brings the seller to the project and still gets HALF of the commission?