[martin417]

After having spent many hours acting as a high school swimming timer, I can tell you that this is a similar situation. There are "touch" pads at the end of the lane to automatically time the touch, there are people standing at the end of each lane with a manual trigger that is pressed when the swimmer touches, and there are two people with stopwatches that back-up the automatic system. Simple triple redundancy. If everything works, the touch-pads are the official score. The manual trigger is the backup for the touch-pads. In the event of a total system failure, the stopwatches are the official time.

Why not do something like that?