From what you said above I can suppose that the right engine thrust remained locked.
Is that it ?
Yes, after the autothrust disconnect, at 18:48:29 (cf. p. 3, FDR graphs).
In case of an "involuntary disconnect" of autothrust, i. e. any mode of disconnect other than bringing both levers to idle or pressing the pushbutton on the lever side, thrust remains locked. Until the levers are moved.
Bernd