As I understand it that's one of the reasons Rod Kobayashi Sensei changed the kotegeashi in Seidokan. With the way he had learned it uke would slap nage on the back as they went over. He felt that if uke could slap your back they could hit your face. He changed the "standard" kotegeashi in our style to a variation I've seen written about here on AikiWeb. Instead of twisting ukes wrist to the side we kind of roll their arm up. Bringing the elbow under the hand and taking the whole thing straight down. It results in uke sitting down instead of flipping over.
Again, that's how I heard it but I wasn't there so take it for what it's worth