Its only half baked information. Aint mention anything about kubelet. I believe when the pod is deployed with pvc, kubelet is responsible for calling mount and unmount operation by calling appropriate driver. Kubelet understands the driver when the driver node registrar registers a particular node on the kubelet.
Unfortunately, very hard to follow. Lots of breaks, lots of "err .. I deleted a slide" and "hold that thought"s - I couldn't really listen to it
says he is going to unravel csi operations then proceeds to skip it :(
Interesting talk to help understand how a CSI driver works.