Ted Ehara wrote:
To my simple way of thinking a kote-oroshi is just a kote-gaeshi done right.
In the Ki Society kote-oroshi is practiced without atemi. However, atemi can be used in both kote-oroshi/kote-gaeshi.
My experience is that we were doing kote-oroshi long before the name change from kote-gaeshi. I was told at the time that the name change was simply to more accurately reflect what we were already doing. That in Japan new students were hearing the description 'kote-gaeshi' and tending to get the wrong idea. For non-native speakers it just is a label change. Nothing changed in how the technique was being taught.
The need for atemi with a resistant uke seems to me a question of how you are moving in relation to uke and whether you have allowed slack to develop. Ideally, if kote-oroshi is done successfully, no slack develops, uke's balance is compromised, and the need for atemi does not arise. If your technique allows slack and/or exposes you to a strike/grabbing range of your opponent then serious atemi is needed as a distraction.