I'm having this problem, which I believe is a bug: when clicking on the "Don't reconcile cell" button, after clicking on "Search for match", that action affects all identical cells.
You could think, as I did, that I could set "Match this cell only" before clicking on "Dont reconcile cell":
But then that button doesn't work at all. Thus, there is no way to tell OpenRefine not to reconcile that single cell. At least, on this window.
Is anyone else having the same problem?