Some of the staff were up in the booth and they would tell Lynn what they were seeing. As the season went on, Lynn probably made more calls on his own (that's just my view of what a I saw). Lynn was never in the booth. I'm not sure if he has ever been in a booth for a pro or college game. He may have been in a booth at Baltimore.
Collaboration was key. Lynn listened in the headsets for help. I would say Lynn made the final call but he had a lot of help.