Cameron is able to show that she is very different from Sarah and John. She shows apresiation for Eric (he is a happy person) something she does not see very often. She takes time to worry about him even though he is not her mission. Shows that Cameron can care...but for the moment. She is a machine. Eric was valuable and she propably did care but once he was removed someone else was easily able to take his place. How very human...to forget about the people who are no longer valuable.
Not sure why Cameron has not killed Riley yet. Cameron "liked" Eric but replaces him without a second thought. Riley is an obsticle to be moved.