What was it that triggered the original thread being moved out to pasture? "Atlanta TV station reports..."?. AvHerald reports in part
Police reported the 20 feet long piece belonged to the right wing of the China Airlines. The flaps section, that separated from the wing, broke in two parts, impacted the fuselage causing substantial damage to the fuselage, too, and fell to the ground.
I'd have to guess (but profess ignorance) that the failure occured on or soon after deployment, and loss of the surface created a serious pucker effect in the cockpit. Good thing "impacted the fuselage" didn't include any of the flying surfaces at the back end.