If you could have filmed it in ultra slow motion, what it looks like to me Ryoon and is that first, your handle riser glue joint failed then with no longer a riser for strength, the handle section broke not being able to take the stress. That's really too bad.
You do have a lot of length there. Another way you might salvage is to redraw a handle at the fadeouts, W-splice them then glue on another riser section. Glue failures can be for many reasons. Too much clamp pressure (starving the glue joint), glue surfaces glassy smooth, lack of pre-sizing the gluing surfaces and/or the glue itself to name a few. I've had delamination problems with hickory backed board bows using TB-II. I am beginning to work with TB-III and am liking my results so far. I scraped my glue surfaces with a fine-toothed sawz-all blade then removed any loose, hanging small shavings prior to gluing. This method seems to give the glue a surface to grab and hold onto.
Or, you could start anew. I think you still have time enough to complete a second attempt. Don't get discouraged.
