You sure about that?????
Donahue studied photos of the presidential limousine and quickly grasped that the jump seat in which Connally rode was actually six inches further inboard and considerably lower than the Warren Commission and virtually everyone else had realized. When the seat was placed in its proper location and the governor positioned as he was when the bullet struck, the trajectory lined up perfectly.
Your point is valid in that once the proper seat arrangement is analyzed, then the trajectory does line up. Thus the bullet is no longer a "magic bullet".