American logs everybody that creates or changes a reservation. If you have the six character "locator" of the new reservation, and a boarding pass from the award trip, you can write a letter to Mike Gunn, he's the VP of Customer Service for American. Include the ticket number (the big set of numbers in the middle starting with 001) from the award trip and the locator of the new reservation, and they'll be able to look up and see who first made the reservation.

If you do write, explain that you didn't get the res agent's name and if the agent can be tracked down and given a "Someone Special (SOS)" award, and if the letter can be added to their records.