1. A method for auditing video analytics data through review of selective subsets of video frame images, the method comprising: obtaining first motion pixel counts from differences within frame images of a video stream of images within a first region of interest that is defined within a field of view of the images; obtaining second motion pixel counts from differences within frame images of the video stream of images within a second region of interest that is defined within the field of view of the images, wherein the second region of interest is different from the first region of interest; determining an occurrence of a first motion pattern within the first region of interest from the obtained first motion pixel counts within the first region of interest over a sequence of the frame images over a first time period; determining an occurrence of a second motion pattern within the second region of interest from the obtained second motion pixel counts within the second region of interest over a sequence of the frame images over a second time period; and determining an occurrence of a triggering alert event in response to a time gap between the first time period and the second time period that is longer than an expected time interval.