Good catch. On the other tower frequency, sounded like a mixup with FLG3199 while AAL17 was downwind, he checked in on the visual to 31L, got cleared to land 31R, read back cleared to land 31R, continued the approach to 31L. Not sure but it sounded like tower noticed the mistake and, with AAL17 extending downwind, decided it would be safe to allow FLG to continue for 31L, recleared him to land 31L ahead of AAL.