In PP CC, you can alt-click a linked clip to select only its video or audio, but you can't alt-click-select a clip's video or audio if it's already selected when alt-clicking. For alt-click-selecting to work you have to first deselect the clip. Why? While a small nuissance, it's these little workflow nuissances that quickly bog down a workflow and generate user frustration.
Could Adobe please fix this? After all, this probably falls into their JDI (Just Do It) category of fixes that can be coded in a few hours.
Thanks. Official FR forthcoming.