Doesn't sound that way to me Lisa. The article is making it clear that they both had access to the computer and with the fees LE are paying that's an angle they are investigating. They want to see what else they can find and just maybe they can prove Lisa didn't post that ad by getting the time and date and proving Lisa was else where when it was done and if it was placed from that computer.
ETA: Remember SP researching tides and currents for S.F. Bay?
Good points, Strach. That's an angle I hadn't thought of. But it could mean that they've come up empty on evidence, too.