Let me please add some points to my POV. First and foremost: I have no criticism about the OP and his group. Their actions were perfectly legal and their roleplay was fine.
Second: I wasn't aware that so many guns were pointed at us. I saw the whole group was about 5-6 people, but after questioning us for the first time, they moved along and it seemed they dispersed. When the OP approached us the second time, at first the situation developed to a "normal talk". The OP was a bit aggressive, but I thought that's how people are when living in a zombie apocalypse for almost two years. When he initiated on us, I was aware of at least one more of his group pointing his gun at us. I wasn't aware of the guy standing at the truck and the guy that shot the video.
Third: Shortly before the OP initiated on us, I heard the "laughter", the common side effect of the Brain Prion Disease. So at least one of the guys was a cannibal.
Now to my main point (and after having time to think about the incident, time I didn't have when the situation was evolving): As a character I was aware we were dealing with cannibals. I knew if I put down my gun, I am at the mercy of these guys. They can cuff me, torture me, rape me and cut me up to eat me. As a player (knowing the rules) I knew if I comply I am safe. But that created a meta-gaming-paradox. From the perspective of my character my choice was to die by complying or at least try to break free as long as I still have the chance to defend myself. Since the OP was counting down from 5, I had to quickly choose which action to take. He was standing in the open unprotected and I had my gun already in my hand. So I shot. It might seem I have broken the NVFL rule, but I think it was exactly the opposite. I was trying to take the little chance I had to survive.
As I said, as a player knowing the rules I know they can't kill me if I comply. That's where rules seem make the game a "safe play". The OP's group knew they were safe, we weren't allowed to shoot because of the NVFL rule (maybe that was the reason the OP initated on us without protecting himself behind an obstacle). Kassander and I should have known we were safe because of the rules for taking people hostage (well, from seeing the video, I know Kassander complied with the OP's orders). From the perspective of the rule (that is not formulated very precisely in the ruleset) I was wrong. But as a roleplayer, taking the situation I am in seriously, I think I reacted in a realistic way.
I would like to ask the administrators to consider this in their judgment.