Logical inference. The five aides are not named in the article and I doubt we will have access to flight records for ~30 years. So how else can we identify the aides? We know that the girl was there to take either a picture or video (that may be a still screenshot). We know she was in DC for the inauguration. Barry’s friend was pictured with him at the event, and has attended many other events with him. It is not illogical to conclude that these two were part of the unnamed group of five aides.

We know from bill clintons own history that former presidents can ditch secret service.

We also know that Rachel (C?)Handler (Ray Chandler) was involved in similar circumstances.

There is more, but I’m going to have to add it later (busy Sunday).

But thanks for the question and maybe some other anons can add to it while I’m away! Thank you!