[This is really a buglet report, but since there is no
bug tracking link configured, I'm writing it as a
feature request --RAM]
In the "Preview" pane, there should be a button "back
to edit" to come back to the edit window.
Indeed, relying on the "back" button is fragile. I've
just been bitten by it: before going back, I did a few
things in other windows, and when I pressed "back", I
got an EMPTY editing screen.
Fortunately, I was able to press "forward" and save my
changes, then edit back the results, but it forced me
to commit an incomplete version.