I've said this maybe a hundred times before, but it's worth saying once again --
Most tellers naturally want to be helpful. So bank management should not be overly surprised when a teller tries to explain CTR concepts to a customer. The trouble is that you cannot depend on tellers -- or anyone else -- to accurately relate exactly what you want them to say, and no more or no less.
The wise thing to do is to provide your frontline contact people with the ammunition to provide a canned, consistent, written response when anyone asks about reporting cash transactions to the government. You should deliver a handout that you have either purchased or developed, and that has been reviewed by counsel. That handout should explain when CTRs are filed and why, and that it is illegal to structure transactions in ways designed to avoid the reporting requirements.
Profit Protection LLC (
http://www.banksecurity.com) has developed exactly this type of brochure. Using it, or developing your own and insisting that it be delivered in place of any attempt to explain the rules, can give you at least some assurance that your staff isn't trying to "make it up as they go along."
I do hope that your HR department puts your employee on probation and comes down hard if there's a repeat of this sort of behavior.