Engine3firehandle....
As long ago as 1992 it was SOP on the Airbus family to carry out full/free control movement and visually check that the control surfaces were moving in the correct sense on the FCTRL system page. Additionally on reaching each extreme of movement you waited 2 seconds for an ECAM warning of control malfunction. This was (and still is) carried out by both pilots in turn.
As the handling pilot's sidestick was cross wired no ECAM warning would have sounded because data to the SDAC indicated that control movement was as commanded. The non-handling pilot in the Lufthansa incident could not possibly have monitored the control check properly as otherwise he would have seen the ailerons move in the incorrect sense.
OK we are all human.... but increasingly now we are the last line of defence. If we get it wrong then we all die.