Harshaw shrugged. "The records show that that cab was in for repairs and was never in use Thursday morning.  That gives us two choices: either a Fair Witness misread or misremembered a cab's serial number or somebody tampered with the record." He added grimly, "Maybe a jury would decide that even a Fair Witness could glance at a cab's serial number and misread it, especially if he had not been asked to remember it - but I don't believe it... not when the Witness is James Oliver Cavendish.  Cavendish would either be certain of that serial number - or his report would never mention it."