Are there any rules within AC that prevent staff from giving a customer a second copy of a boarding pass?

I've never had an issue with this, when I check in, I usually request 2 copies and the check-in agent writes "dupe" on one of them. Everybody's happy.

Today, I used a kiosk for the first time in ages. I obviously only got one copy of my bp. So I popped my head in the concierge's office 10 feet away and asked if they wouldn't mind printing me a second copy. I was sternly told that under no circumstances are they allowed to give me another copy of my BP.

I said that it has never been an issue in the past, including last week, and she informed me that there were two reasons that she could not comply. One because I could submit one of them to another frequent flyer program and get credited more miles. I said...but I could do that if I only had 1 copy of my boarding pass...and I wouldn't get very far with that ploy. I also said that if I had printed at home, I could print as many copies as I like. She then told me it was a security risk and reiterated that she would not do it.

5 minutes later in the lounge, I asked a lounge agent for a second copy. He printed it, wrote "dupe" on it and everybody's happy.

Any thoughts? Are there official or unofficial rules for this?

BTW, the reason I get two copies is for my own record keeping. I know I could make a photocopy, but it's usually more convenient to get 2 copies at the airport.