Let me give you a very personnal example, for 10 years I had to check people in/out at my Grand mother's house especially for workers (is this right word in english ?) how came every day to make her eat and wash.
So I had to count each time they come in/out and also how long they spent at home and for this the motion recording was fine and rarely missed an in or out (but yes it happened), I also developped my own "fast video review" tool, very optimized to do a monthly check/report with semi-automatic sorting (using auto x10 time play speed, keyboard shortcuts for deleting or moving each video to dedicated worker's folder (key 0-9 as I never had more than 10 different workers) and adding a "in" or "out" at the end of video's filename, so the time each one spent at home could be automatically calculted by an other software I developped on purpose and then double check with the company's bill, very usefull and permitted to detect some workers that did not wrote the correct timing (whenever they knew about the camera that's weird).