Umm... I think he said a lot more than "it's not visible on video, so we can't confirm". I think it's clear that whatever supposedly happened at 3:38 *should* have been on video, but was not (or at least, LS was not part of whatever was on video). He did not just say the 3:38 sighting was unconfirmed, he more or less said it was false.
That's exactly what I understood from that press conference. He appears to be pretty confusing in general, but I think he was very clear on this.