Given the ticket scalping problem at Hamilton, one solution may be to go to the box office now--in advance of the show-- and explain the concern. Your friend may be able to just exchange the tickets for ones printed with a new bar code.
I had a problem once with an envelope arriving in the mail from Ticketmaster that had been opened, and though my ticket was in there, I was concerned about the barcode. So I called Ticketmaster and they voided that barcode, and issued me a new ticket. I was just thinking that the box office should be able to do something similar, though I don't know for sure.