I was convinced later during the debate that he rotated note cards during a response.
I spent all day Friday trying to find the clip. I saw it on FOX news during the debate, but it did not show up on the CSPAN angles.
WaPo has the full video. If it's in any way different from C-Span's, maybe you'll see something. Google "presidential debate full video"--let me know if you still need a link.
I remember expressing some surprise that Fox was out front in griping about having no camera flexibility--didn't seem in character, but I wonder if they had a clue that the Kerry camp was going to game things.
There's a idea! Where else in the video might we focus on this "pen"?