Possibly a magical awesome bug?
I had just recruited some fresh newbie humans for bogey duties, a hammerman and a spearman.
During the first day, we were ambushed by kobolds twice. The first battle went OK, but the second had two bowbolds, and my friends got a lot of chipped bones.
So, after stabbing the last of the enemies in the brain, I wandered back to my buddies... they were both out cold.
It didn't look like I could get both of them awake on the same frame to fast-travel and get them healed, so I opted to take a nap along with them for an hour.
When I woke up, they had vanished, although I still had them as companions on the 'c' list.
I even walked to where that list said they were, but couldn't see anything.
Thinking they were goners, I fast traveled a square.
And then they were back!
Given the grievous wounds, I was expecting them to be pretty useless equipment-wise, so I took a peek.
One of them had a second shield equipped!
And the other was now wearing a crown made from Kobold nails!
We were shortly set upon by a whole pack of giant dingoes, and got torn to shreds, so I savescummed and took a look at their original equipment at hire-time.
Just one shield apiece, and no fancy headgear.
I'm going to try this again!
An hour's nap after my companion gets a named kill or there is equipment lying around for him to take.
I also want to try dropping a pile of weapons and shields at his feet before napping.
!!Science!! beckons!