Originally Posted by
coutura
Generally a transaction like this should be refunded by refunding/reversing the original transaction (not just issuing a $XXX credit to the card). If this is the case, then I would think that the CC issuer would also waive/reverse the associated fees. United probably did a separate transaction crediting your brother's CC with the amount of the ticket.
I've written credit card software and never heard of reversing a transaction. You can void a transaction before it settles (typically same day), which will have it not appear on the cardholder's statement, but that's not always possible, even within the same day.
A "refund" or "reversal" is really just a "credit" behind the scenes -- applying a credit for the same amount of the original charge. Many merchant processing networks require a credit to be refunding all or part of a transaction ID in the past, but that is a security measure to limit credits to the total value of an original transaction.
What you're probably confused by is that merchants can supply additional transaction parameters including PNR, passenger name(s), origin/destination, fare classes, etc, that appear on the credit. This is for your convenience when reading your statement. It's just an arbitrary credit that has some arbitrary text that may look just like the original charge.