here's a postulation
If the anti-Ice was stuck on and operated in an warm ambient temp conditions (low altitudes) , the cowl would overheat weakening the composite walls. Then if the engine were increased to very high power while the aircraft was at low speed, with less ram air into the inlet, the sucking pressure drop across the inlet would act on inner panels and possibly delaminate them at their attachments. Since the inlet walls are made as panels, only the weakest one would fail.
This is only a postulation that might serve to provide some additional thoughts and checks to some confirmed reasoning.