Lo-Fi Games

So two of my characters were captured by bandits.
I started off as a wanderer and later rescued a named escaped holy servant from some Fogmen and he joined me. As my character had just recently escaped from a holy mine himself, or herself (i don't know it's a hive prince).
So we got captured in our quest to avoid the holy nation and I decide to free some other prisoners, either for there sake or to create a distraction either way. I talk to a berserker and pick there lock and we proceed to attempt to sneak out. after a long and arduous battle we won and the berzerker who had been following me was now a part of my squad!
Long story short: This is awesome.
But I was wondering is this a bug that I benefited from or is there a way to get others to join me based on my choices and interactions?
I Just thought this was cool and wanted to share.

Yeah, that's really great, also 'cause it happened by vanilla game rules, rather than any mod (e.g. Recruitable Prisones)

Yes when you free prisoners, (that you don't imprison yourself), there is a chance that they will join you. They generally follow you around till you are out of the area they were imprisoned and then they make their choice.