My suggestion would be getting rid of that section entirely. It doesn't make any form of sense anyhow. A bunch of gun nuts trying to use violence to preserve culture is in itself a contradiction. Even if I had said yes to their demands, what possible ways would they have had to make sure I kept my end of the bargain?
By trying to use violence they put themselves at a disadvantage from the very start, especially given their cause. And when I did predictably refuse, by killing me they achieved nothing at all. They had a need, I had a way of satisfying said need which means I had the upper hand and nothing they did helped to promote their cause. There's just no logic in any of it.
It would have made more sense at that point to kidnap me, but even so there's just no plausible way for them to get a lasting deal out of that, as once they release me I would be more likely to spite them. Kidnapping someone dear to me and holding them ransom would also make sense. But really, given their objective, what would have made the most sense would have been to at least have tried to present their case verbally without any threats. Maybe even trying to bribe me, try different angles. Guns blazing is a means of desperation and stupidity, and in either case given their cause; a more valid last resort would have been to secretly smuggle in cultural treasure.