I rejected an ICAO licensed applicant for a UK CAA flight test a couple of years ago, based on the discovery that he had not completed training sufficient to qualify for the issue of a JAA night qualification. UK authorities came back and said that anyone holding an instrument rating was night authorised - but I pointed out that that authorisation was based on the assumption that a night qualification was a prerequisite of being able to attend the training course for the UK instrument rating.
That's an interesting one.... " anyone holding an instrument rating was night authorised"
All this means is that somewhere in ICAO-land, one can get an IR with less night training than is needed for the JAA NQ.
In the same way as one can get a JAA PPL/IR, and probably a JAA CPL/IR, with less night training than is needed for the plain simple FAA PPL.