IMHO, Spock comes off as a creep in that scene.
Here is my take:
Rand is trying to tell Kirk that she understands it wasn't really him doing those things; that she knows he would never do such things in his right mind. She is trying to help him not be uncomfortable with her because of what happened. Kirk senses how uncomfortable she is, and he is also uncomfortable, so he says "Thank you, Yeoman" to let her end the conversation.
Meanwhile, Spock jumps in with basically, "yeah, but you really kind of liked it, didn't you?" About the "evil Kirk" nearly raping her. Really offensive and not even justifiable by saying "well, it was the 60's and things were different." This one even goes beyond that line.