I just had one of those... ?Que? moments.

I was on the Bleed Me Dry quest for The Thorn. Last part with the Deathclaw eggs. I decided I wanted to fetch them in Dead Wind Caverns and off I go. After murdering all the Deathclaws outside and inside, I loot the last few corpses. Then suddenly the screen starts zooming in and out like if you pressed the right mouse button a few times. That was weird. Then my screen pans over to an NPC behind me, as it does when an NPC urgently needs to talk to you. Behind me stands a Powder Ganger and 3 Great Kahns. The Powder Ganger says some generic line and exits the conversation and the four of them are just standing there.

I'm not quite sure what this is all about. Weird bug if you ask me. I've been on fairly good terms with the Powder Gangers ever since the start with Goodsprings and I'm Idolized by the Great Kahns. Were they supposed to attack me? The three Great Kahn's could look a bit like the ones I get out of the hostage situation in Boulder City. I resolved it peacefully, but that was ages ago ingame. The named Great Kahn from Boulder City has been in Red Rock Canyon for a long time though his conversation still implies that he's on his way. I have recently done the Great Kahn quests Oh Papa and For the Republic, part 2 but I have no idea if that's related.

Just when you think you've seen everything.

Has anyone else had a similar thing happen or something else weird in the same location?

There is another group of 3 Khans, that quest comes from the mine town near where the deathclaws are.

However, it sounds like a weird glitch. Do you have a save from just before you went into this cave? I bet it won't happen again.

I had some random Khans appear with my in the NCR Embassay (Took out all NCR and stopped me from doing For the Republic pt.2 but after a reload they were gone)
It's also happened in my NoVac home and a few other places

I've had random NPCs suddenly spawn myself - it seems to happen in the Lucky 38 suite in my games. Cachino from Gomorrah showed up there once, and that Followers lady who gives you the Moon Comes Over the Tower quest popped in for a visit once. In each case they just spouted one line of their generic dialog, and then left via the elevator .

The Khans show up EVERYWHERE.

People have reported them bugging and appearing in Nellis, Black Mountain, Old World Blues....everywhere.
They get around.

I once exited Helios One out the back door and there was Old Lady Gibson and her dogs. Funny thing was the dogs all went crazy and killed her, then attacked me.

Why i want to stay friendly those [censored]

Yeah that happens to me all the time, theres this loud thud and then they fall over the side of the building and start fighting, I just walk back to her house though and shes sitting there fine and happy.