So I strung up my small sapwood/heartwood Osage bow today and took a few shots. I must have put 700+ through it already. It pulled about 43# @ 27" and was 46" ntn with a stiff handle. Yes, you're correct, it was over-stressed and today I paid the price.
You can see the hitch in the lower limb's fade where the failure occured:
Here is the splinter that lifted on the back, and the chrysals that had already formed at the exact spot on the belly:
I even wrote a blog post about how this bow is testament to Osage's forgiveness. Looks like I spoke too soon
In retrospect, based on the tiller alone, there is no reason I should have deemed this bow fit to shoot.
Now it goes back on the wall to remind me of lessons learned while I work some other staves. Eventually I'll take it down to repair it with some super glue and a sinew wrap, but I'm not too confident it will help.