I believe that is why it's safest to shoot raw, and open a copy to work on, leaving the original raw untouched...
or even if you shoot jpeg, open a copy, rather than editing the original..
with paint shop pro I can open a file edit as much as I want and with the settings I chose, the original is saved untouched...
I can also save the edited file as a paint shop file, which then saves the original file and the edits, so when you open it again it then applies the edits, so your original never really changed..