1. A method for auditing video analytics data through review of selective subsets of video frame images, the method comprising: a processor obtaining motion pixels from differences within frame images of a video stream of a scanning station for 1) a pick-up area region of interest that is defined for a pick-up area of the scanning station, for 2) a scanner area region of interest that is defined for a scanner area of the scanning station that is different from the pick-up area, and for 3) a delivery area region of interest that is defined for a delivery area of the scanning station that is different from the pick-up area and from the scanner area; the processor unit distinguishing hand motion patterns in sequences of the obtained motion pixels within each of the pick-up area, scanner area and delivery area regions of interest; and determining an occurrence of a triggering alert event in response to a time gap between the hand motion patterns that are distinguished within the scanner region and the hand motion patterns that are distinguished within at least one of the pick-up and delivery area regions of interest that is longer than an expected time interval.