There wasn't a lot of employees. Just about five people, all known, who set up the LLCs, website, and worked with the shifty banker to funnel the illegal online gambling funds through credit card entities.
If he was defrauded, it wouldn't be hard. I know where to find the list of Johnson's shell companies. I've gone through it, a couple of times. There's about 78.
All we'd need to know is if he ever filed a credit card fraud complaint, and then see if the name of the company appears on the list.
As for working for him: I think we'd already know. Until just the past few months, it was quite the feather in one's cap, to be connected to "philanthropist Jeremy Johnson".