I missed this thread previously and have been made aware of the photo by Geoff Welch.
I think this is almost certainly a first-winter Northern Hawk Cuckoo (which would only be thr fourth HK record and the first since 1997).
It is clearly not Large Hawk Cuckoo as the wings are too long. Although you cannot see the tips of the longest primary the distance between the wing tip and tail tip (outer tail feather on L side can be clearly seen) is actually very short (and possible too short even for Hodgson's).
In terms of plumage the clean white (rather than off-white) underparts with bold black (rather than brownish) streaking fit Northern rather than Hodgson's.
The date is later than any previous Hodgson's record, for which 24 August seems to be the latest record (contra the entry for this species in the 2007-08 Bird Report) but somewhat earlier than any of the Northern records which span 29 September to 27 October.
However, any additional photos, especially those which show the true extent of the primary projection anf the tail pattern would be most useful in clincing the ID.