Physical evidence trumps "opinion".
That Oswald's prints are on the bag is indisputable.
Therefore:
-- How did Oswald put his prints on the paper bag?
-- When did Oswald put his prints on the paper bag?
-- Where did Oswald put his prints on the bag?
Physical evidence trumps "opinion". So true. And what you've got is an opinion.
What exactly is a bag, made from TSBD materials and found at the TSBD in a location where Oswald worked, physical evidence of, to you?
-- How did Oswald put his prints on the paper bag?A possibility?... He picked it up to move it from a box of books he needed....
-- When did Oswald put his prints on the paper bag?Who knows?... He could have picked up the bag on Thursday or even on Friday morning.... There is no way to know for sure.
-- Where did Oswald put his prints on the bag?John already told you. I'm not really sure why you would ask him for proof, since that suggests that you have not considered all the evidence when forming an opinion.
Anyway, a far better question is; Oswald is supposed to have made the bag at the shipping department of the TSBD, folded it to take it to Irving (without Frazier seeing it), opening it up again and put a rifle inside, carry it gripped at the top and letting it hang next to his leg (Randle's observation) and carry it with the bottom in the cup of his hand. With so much handling, why were there only two parcial prints of Oswald found on the bag?
And some more questions for you;
There were more prints found on the bag, which could not be identified. Could this mean that others have also touched the bag?
When the bag on the 6th floor was found it was allegedly folded up. But it was carried out of the TSBD unfolded and a photo shows the unfolded bag on top of some boxes in the sniper's nest. Who unfolded the bag and put it there, and why have that person's prints not been found on the bag?
Frazier told the DPD officers on Friday evening that the bag they were showing them wasn't the bag he had seen Oswald carry, so why do you think it was the same bag after all?