When a kokyu-nage is being applied to us, we move our bodies in a manner that allows us to remain safe. If the attacker does not do so, because he/she is so intent on taking you to the ground, or continue to strike you, the attacker might very well end-up with eyes gouged out, being choked out, or having a neck broken. Those endings only become difficult to execute if we begin to tense-up, and/or try and impose our will on the person (breaking the harmony).