I think he means Oswald was aiming at the head therefore two misses.
Don't forget he missed the first shot by a good margin, not-to-mention his Walker miss at shorter range. Given those failures, one could posit that Oswald may have decided to aim center-mass on the twofer. He did indeed land one 2" from the spine, and about center on the vertical plane (reasonably equidistant between the top of the head and the backrest.
If 'bang-bang' is true, it seems he would have no time to aim precisely... just point-and-shoot and hope to get lucky. (The HSCA tests revealed that the rifle could be fired in 1.67 seconds, but most (if not all.. I don't recall) of the shots missed, only the first could be aimed precisely, and the second one could only be pointed.)