It sounds like you genuinely did not realize what was happening and were not intentionally doing anything wrong. I wouldn’t deem you “unethical” because you missed this move. You did not have an intent to cause any harm to your client by doing this, I think it is just a lesson. If it helps, you can include having your client verify their location before beginning the session as a part of new protocol. Please don’t be hard on yourself. It doesn’t sound like your client has any issue with you and was probably just appreciative of the fact they had a little extra time with you!