The user just requested that the file be overwritten when they said "save". Clearly the content of their "precious" file doesn't matter any more, its the contents of the Geany buffer that the user wants to save that is important. And as the wiki article says, failing to save does not alter the Geany buffer, its still available to save somewhere else, whatever the reason the save failed. Save to a usb stick, save to a different drive, just save that precious buffer, and don't worry about the old file, they already said to overwrite it.
Okay, but the user *does not know that the original file was destroyed*. There are cases where the file was only slightly modified (in my case I added only one line to the file), and one says: okay, there was a problem when saving, but at least my original file is safe, let's quit Geany and see what happened. An what happened is that the original file is now empty.
But I don't even understand why I have to argue here. That's simple: data loss in a software *must be avoided*, period (excepted in case of hardware problems, of course).