You mean a contradiction that only occurred in the minds of the LN?
You need to read the conspiracy advocates a little more closely. They believe in all kinds of inconsistencies. Such as the one above. Visit the assassination sites and spend a day or two. You'll be amazed.
A good number of conspiracists believe JFK was shot from the front and then all of the evidence was altered to show he was shot from behind. The films, the x-rays, photos....all altered.
Does that make a damned ounce of sense? What idiot would try to do something like that? In broad daylight with hundreds of people around and some with cameras?