Analyse the following 16-line dialogue. From a professional hospitality perspective, what specific security error did the receptionist commit when handling the guest's request for a replacement key?
Guest: Hello, I'm very sorry, but I've lost my key card while out for dinner.
Receptionist: Welcome back, sir. Do not worry, we can sort that out for you immediately.
Guest: Thank you. I'm staying in room 204.
Receptionist: I see. May I have your name, please?
Guest: It's Mr. Julian Vane.
Receptionist: Thank you, Mr. Vane. I have your reservation here. May I see some photo ID?
Guest: Oh, I've left my wallet in the room. I have nothing on me but my phone.
Receptionist: I understand. In that case, can you tell me the last four digits of the credit card used for the booking?
Guest: Yes, it ends in 4492.
Receptionist: That is correct. I will print your new key card now.
Guest: Many thanks. I was worried I'd be locked out all night.
Receptionist: Not at all. Here is your new key. Your room is on the second floor, the third door on the left.
Guest: Excellent. Does this card work for the late-night entrance too?
Receptionist: Yes, it grants access to all guest areas. Is there anything else?
Guest: No, that is everything. Goodnight.
Receptionist: Goodnight, Mr. Vane. Enjoy the rest of your stay.