Uh FliesWay2Much, I can't speak for the TSA person, but my guess is s/he was trying to pro-actively offer you the privacy that GradGirl says she wants (although in her case she wants it so she can be obstructive), not because s/he was 'afraid of something'. But odds are thx to your response someone else might not be offered that option in the future, or will have to request it rather than it being offered up naturally.

Sharon