blaggerman
Indeed, you are correct. There is indeed a feature of booking and also the Executive Club that will allow someone to add a 3rd party nominee to a booking, to allow the booking to be discussed and managed by someone else.
However, this was not done. Likely because the OP was not aware that this needed to be done. Which, is not fault of theirs.
It was an unfortunate situation, which could have been dealt with differently by all involved, not just the carrying airline.