With the missing afterbody, would you not expect in-plane chordwise oscillatory forces at the cap to increase dramatically?
With the TE wedge long gone, the skins are no longer contributing to a "torque box" at the attachment location for the cap.
I don't doubt in testing the cap would survive a plethora of overspeed and other conditions...but that is with, at worst, and intentionally placed flaw within the laminate on a fatigue test - not missing an entire afterbody!