When a consumer reports a dispute and in interviewing the customer it becomes evident that this is not an EFT "error" because while the consumer unfortunately was a victim of a scam, they did in fact authorize the payment themselves, is this triggering the "no error" EFT letter to the consumer or can we verbally tell them that since the transaction was authorized there is nothing we can do?

The customer reports a dispute - that triggers coverage under Regulation E error dispute rules. The interview with the customer is nothing but a part of the investigation.