B.J. would not be able to lock or unlock Boss's desk just by turning his pick-tool inside the middle portion of the lock like an antique round-shanked door/drawer key would operate; the lock on Boss's desk-drawer is a flat-bladed-key lock which has to have its whole cylindrical tumbler-barrel turned to operate it.
At 45:51 you can see Bo duke's reflection but it is clearly a stunt man as he has dark hair instead of blonde.