Mold is a significant issue for home-growers (and home-rollers) of tobacco. Understanding which of your handling and storage choices make a significant difference in mold growth is important, and not a subject that benefits from inaccurate information. It's straightforward mycology.
Contamination is not the determinant of active, vegetative growth of mold on cured tobacco. It will always be contaminated. The humidity, or more specifically, the moisture content of the leaf stem or lamina, will be either sufficient for vegetative growth of mold or insufficient for vegetative growth of mold. If the moisture content of the tobacco is sufficient for vegetative growth of mold, then the tobacco will mold.
The extent of spore contamination may, if only slight, slow the spread of mold growth by a reproductive cycle or three. Once there is vegetative growth, the sporulation cycle explodes the growth exponentially. What this means is that if the contamination is slight, then the minimal duration of a span of high relative humidity that might present a risk for significant mold growth may increase from a 3 day average humidity to maybe a 5 or 6 day average humidity. That might or might not make a difference.
Bob