When I open split view and I explore other folders in the panel that was opened, split view should close on the panel that I have currently selected. Right now it always closes to the panel that it was originally opened from, regardless of focus or selection.
I also often find myself unable to predict which pane will be closed, which reduces my confidence in the feature and willingness to use it. If we make this change, we'd want to also change the button and menu item text to say something along the lien of "close active split view"
*** This bug has been marked as a duplicate of bug 312834 ***