Wesley said that the bag he saw Oswald carry was not CE 142. Do you see a reason for him (then or now) to lie about that?
Yes. To avoid being prosecuted as an accessory to murder.
The Dallas Police spent hours grilling Frazier, trying to get him to confess to knowingly transporting Oswald and his rifle, in that bag.
Under the circumstances, it was natural for Frazier to convince himself that the bag he was presented with could not have been the bag he saw earlier that day. That indeed, the bag he saw was actually too short to carry a rifle at all.
Of course, I don?t think that Frazier was lying. But it would be natural for someone in his position to convince himself that this was not the bag and the bag he saw was too short. And the same goes for his sister who was, I imagine, upset to learn that the information she provided to the police was now being used to try to get her brother to confess.
If this does not count as a reason, what would count as a reason?