This happened in version 1.2.0 p23

Upon arrival at the TotHK I stumble upon an out-of-the-"box" SK, with a bunch of minions already summoned (probably due to having detected the PC).
PC is an Orc Barbarian lvl16 (raised to 17 after killing "boneman") that took a peek inside Darkforge and FGJC5 (GUV turned him back).
I've never seen or heard of such a thing happening. I'm still fairly unexperienced (the farthest I got was the fire orb once) but I'm as spoiled as I can be. My question is if this does happen sometimes and what causes it, or is it a bug?