I think you were ok, and I know I would have been uncomfortable as well. As for trying to figure out who Rusty was, well, if he was drunk most of the weekend, or at least when you got there, maybe not the best time to play 20 questions and get to know you. And as I am not comfortable around people I don't well init8ially, esp spending a weekend sort of isolated with them, I would probalby have acted the same way you did.
I had something happen to me one time, which thankfully had an ok ending, but many moons ago, I had a friend who shared a house with 3 other roommates, all were female, including my friend. They all had a big Halloween party, to which I went with a couple other friends. I didn't know her roommates at all, just my friend. Anyway, at one point, my friend, another friend of ours, and host friend's cousin went to her bedroom for something. Cousin then proceeds to take out a gun, and had previously been talking about buying so many hits of LSD! I was justifyably freaked out, as I didn't know her cousin either. And it turns out she had come from work, and was trying to find a place to stash her gun for a bit during the party, whcih is why she took it out to begin with.
Who is this person, talking about buying drugs, and with a ginormous gun? Turns out, she was a cop, and looked young enough, they used her for undercover buy nad busts in the local HS. THAT is what she ws talking about. But I was