Looks like a good subject for a Congressional inquiry to me. I’d make contact with the local district office to see if they can assist. Perhaps it’s just a paperwork SNAFU from checking a wrong block on the application - hope it’s an easy fix for your friends. I agree that it certainly doesn’t pass the “smell test.”
She's going today to the embassy in Pretoria for an in person interview appeal... hope it goes well.
This does not surprise me at all. My foreign fwife had to apply several times before she was finally able to obtain a tourist visa.
In Tanzania couples traveling together are often denied Visa by the Tanzanian government. If one of the couple’s decides to come over for business and leaves the spouse behind it’s usually approved just as long as it doesn’t appear that they are traveling out of the country and not returning. But as I said it’s the Tanzanian government that denies the Visa in that case. Are you quite certain it was the US that denied the Visa or was it the South African government that denied the Visa?