I would venture to say that at least some of the so-called "bloom" (or "plume") on cigar shop cigars is, in fact, mold. Sometimes they are inadvertently over-humidified. Since mold spores are ubiquitous, that is a risk. In the half-century of storing my own cigars—hundreds of different brands over the decades—in my own wash-stand-size humidor cabinet, and some of those cigars resting in there for a decade or more, I have never seen "bloom".
Note that the photo in the above link seems to show "plume" predominantly at the cigar head. If, indeed, those are crystals of something, then their location would suggest that they are related to the cigar glue that was slathered onto the heads to make them pretty.
Just an observation.
With regard to the Cavendish with mold, it does not pose a significant health risk if it is smoked in a pipe. Any possible aflatoxin present will be combusted. On the other hand, if it smells like mold, it won't be very nice to smoke. Moldy tobacco does present an aflatoxin risk if it is used for smokeless preparations or for cigar wrapper.
The only time I have seen moldy Cavendish in my own tobacco is when I bagged about a quart of my first ever batch of Cavendish—in medium case. I had judged it to be less squishy than commercial Cavendish. A lesson learned. It looked like mold, smelled like mold, and was sadly tossed out. I now store Cavendish (which is more hygroscopic than uncooked tobacco) dry enough to crack but not crumble.
Bob
