My take on it is, that kotegaeshi isn't a technique to throw down or to immobilize or anything like that.
It includes a principle and is just another way to exercise, smoothen out and strengthen the body and rather show how it can move and where the limits are.
Actually, unlike in judo or wrestling, I have yet to see the kihon waza in the aikido curriculum, that would really hold down or immobilize a decent noncompliant fighter, per se. And you get trained to get thrown.
Of course, you can be injured.
But in my experience, most of, if not all of the injuries happened to complying partners, when nage lost control over himself.

Best,
Bernd