You can loose a thousand amateur fights and still have a perfect pro career. There is no contradiction.
Did he ever make the claim that he never lost a fight either amateur or profesional during this period?
A statistical abnormality that he atained on his merits.
Point one; of course
Point two; Marciano claimed to be unbeaten from March 1947
Point three; Well no, as well as Wallace, the first LaStarza fight was a draw...