I knew a guy who knew a guy who had a pink snake that was like a 100 feet long.
When someone sells 100s, 1000s? of animals there are going to be stories but until someone says I bought a snake from ___ and it had mites and they did nothing to help me then I'd place more credence on it. He has a big operation could a snake leave with mites... it is possible sure. The only way to be 100% sure of the animal is to see it in person, and have visited the breeders facility a few times in the past before the purchase. It doesn't sound like a BHB or not question to me it sounds like order or not, question. If you are really that concerned find a local breeder and go see the facility if they will allow it many will not. Make a decision on what you see.