Soft bones in smoked chicken For lunch today, a coworker and I went to a neighborhood southern-style BBQ joint. I usually wind up with fried catfish and he fried chicken, but today we both sprung for the smoked goods, and I found myself ordering a barbecue chicken leg sandwich.

After ordering, I thought "I wonder how that works... legs on a sandwich?" I figured that meant is was leg meat. When Mabel brought it ought I was a bit surprised (and slightly disappointed) to find that this was whole chicken legs on top of two slices of white bread. Oh well, I'll just pull out the bones.

Then the strange part happened. I picked up a leg to start pulling on the bone, and it collapsed under its own weight. Well that was the exposed part of the bone... it must have just disintegrated. So I started picking the meat apart to get to the bone, and when I found it in the middle and squeezed it to give it a yank, it collapsed under the pressure of my fingers. 

As I worked my way through all the bones in the legs, I found this pattern continued: all of the bones were not just brittle, but downright soft! It was a bit hard to pick it all out, and I think some even got left behind in the meat--and even still it was barely even noticeable when chomping down.

What would cause bones to become so utterly soft?

I assumed Mabel must cook these things for a week, but when I asked, she said it was an hour or two in the smoker. Does smoke really do this, or is there some other treatment.
Boiling chicken bones for an extended period of time (4+ hours) will cause bones to go squishy.  I'm assuming any long duration slow cook method will do the same.