Considering this happened  in exactly the same way on a second piece I am convince it was too dry.  As far as forcing I really doubt I did that as I never go above target weight during tillering.  The target weight of this bow was only 45lbs.  And I'm pretty ginger with my new bows during tillering.  I alway exercise them well and always pull them to draw weight 30 times after wood removal before I judge tiller.  I nurture my boards during the bow building process  
 
  I turned out 3 d-bows previous to these two with near perfect tiller(according to you guys 

 ).  I got 4 pieces of red oak at the same time back in september.  I made 2 bows right away from those 4 peices.  One of those 2 was a 64" long 1" wide red oak drawn to 28" @41 lbs if any of them were overstrained it was that one.  These other 2 pieces sat in my entry way for the last 2 1/2 months.  I thought about the fact that we have entered the dries time of year in one of the driest states in the country and the wood was sitting in the driest/hottest part of my house.  When I made the first 2 we had just exited our monsoon season.  The suggestions of being dry makes sense to me.
So I will reevaluate how I store my bow wood from now on.  
As far as that Ipe, how long should I let it sit in a humid area to regain some MC before I start working on it?  How many showers should it take with me  

??