Gyaku Gote and Kote Nage are similar techniques. Many people perform a version of Gyaku Gote which is almost indistinguishible from Kote Nage.
When is it Kote Nage and when is it Gyaku Gote?
BTW - I thing that the answer is a bit deeper than Gyaku Gote is a defence to a grab and Kote Nage is performed against a punch to chudan.