If you can accept from the totality of facts and known circumstances that it is extremely unlikely that Oswald carried any curtain rods in his bag, then you are on the road to enlightenment. The next step on your journey to reality is to ask why Oswald would lie to Frazier about the contents of his bag if it contained some non-incriminating exculpatory item and why he would deny carrying any such long bag to the police if that bag actually existed and could be found in the building to confirm that it did not contain a rifle.
The next step on your journey to reality is to ask why Oswald would lie to Frazier about the contents of his bagThat's easy. Both Marina and Ruth Paine testified that they believed Oswald came to Irving on Thursday to make up with Marina and persuade her to live with him again. That's not something you share with a 19 year old co-worker, like Frazier. It's far easier to tell a white lie about picking up some curtain rods.
why he would deny carrying any such long bag to the police if that bag actually existed and could be found in the building to confirm that it did not contain a rifle. First of all, the quality of the answer depends on the quality of the question. In other words, if you ask Oswald what was in the "long bag" when he does not consider the bag long, he will reply with a denial of having carried a long bag. Secondly, Oswald wasn't shown the bag they found at the TSBD, nor was he asked if he had carried a broken down rifle in it, so he had no idea what size bag they were talking about. The interrogation reports are of no value to justify any kind of a conclusion regarding the bag Oswald actually carried and/or it's content.