Our goal with the RFID is to track laps and lap times, not to determine who beat who at the line. As a general rule if a bike is overlapping another bike at the finish it needs to be reviewed. We operate the camera at every race to confirm finishes. I wouldn't count on accuracy beyond .5 seconds with the Tags and Reader from what I am seeing.
Cross isn't a timed event. The times are provided for analysis and training purposes so riders can see how they compare to their peers that are not in their line of sight during the race.
The times at the races this year are not from the RFID but from our old 10 key system. When keying the finish of a race the protocol is to key all the riders first, then hit the timing plunger the appropriate number of times.
If one or two riders are finishing we hit the plunger right as there wheel crosses the line. If multiple riders approach the line at the same time ...lets say 8 in this example, we key all 8 riders in the proper order and then hit the timer 8 times. Thus times may be off by more than a second or two. In a stage race all of the riders would have the same finishing time. I guess we should opt for that method as it would be much easier to hit that group of 8 with the same time.Seattle Cyclocross does an amazing job of getting all the placings correct and published.