The lawyer's office is one block up from the corner on which she was said to be seen. And he only said that she wasn't on the video at the time he looked. Doesn't rule out if she was slowed down for several minutes for example, and it doesn't rule out an abduction before she reached his corner.... my opinion of all the video in this case is that it is only really useful for what it shows, but not so useful for what it doesn't.
Although it is noticeable in that clip how Salzman says (more than once IIRC) that the tape may be as meaningful for what it doesn't show as for what it does. He seems to be implying that there's a problem with JR's story IMO.