How does this happen ?
As soon as all runners had disappeared up the road I unchecked Chip Start option and Stopped Listening. Immediately, a runner appeared as having finished ! As per previous forum input - thanks - I checked Chip Start option again and deleted the clock screen entry to translate it into a chip start. This person was way at the front of the pack and so was nowhere in proximity of the start line when I stopped listening.[In a previous race I did have quite a few more of these occurrences, sadly].
Apart from this, I had one non-read at chip start with over 400 runners (resolved as he declared with whom he crossed the line with) and 100% finish line reads. No issues during the recording. Very satisfied, thanks Brian.