Have you ever trained with Eric Beake? Eric and I used to train together in the old Ryushinkan in Albany Street, London, and it was Eric who first emphasised (to me) the importace of seeing kote-gaeshi as a knife attack, probably with an attacker who will not attack and simply stand there to allow the technique to work.
With kote-gaeshi, especially done as an 'ura' technique, you always need to get into a position to do atemi. The interesting question is where the straight atemi is most effective. Any ideas?