Just part of the wonderful world of common rules that are not commonly applied.
JAR's require you to have done the necessary but make no stipulations as to how it is to be recorded. CAA is more prescriptive. The revalidation requirement is not dissimilar to the the 3 take-offs and landings in 90 days to carry passengers rule. No laid down requirement about how this is to be recorded, nor any requirement for an instructor or examiner signature, it's left to your own common sense to record number of landings if you do them all in one flight, however the UK CAA has heaped a raft of additional requirements on in the case of your revalidation flights. They just can't resist adding their own embuggerance factors to what's been agreed internationally.