There certainly is overlap as well as superfluous information taught in computer science, with respect to robotics, but to say that computer science techniques aren't necessary would be an overstatement.I guess you could be right. I know friends of mine that are much more involved in software who have done neural networks and A* search algorithms. But those can also be taught in a robotics class.
Graph search is another good example.
On the other hand those guys have done database managment and web infrastructure which I don't deem crucial for robotics.
I'd argue neural networks are a computer science topic, but EE has discovered that there are many applications for it, particularly in robotics, so it is taught in some courses.