Outside of handling confidential information on non-secure channels, the issue could the authentication. You want to be sure it is actually her approving it. A

Outside of handling confidential information on non-secure channels, the issue could the authentication. You want to be sure it is actually her approving it. Another issue could be about the quality of the briefing: if the phone call was all she got, it might mean that she wasn’t briefed enough to review the evidence and make an informed decision. However, I think that this just goes to the line: she was reckless with confidential information — which, at this level, is against the law.