Re not checked into CVS (yet):

For just such an emergency, I have automated daily backups of all my "work" stuff. Overkill, but disk space is cheap, and "just in case".

I also published a "Cheap Mirror" utility that is a proof of concept (under Win32) for doing autobackups when a file is saved, essentially remembering multiple generations of a file.

More musings...
I don't like the "trash can" thing where files aren't really delted until I empty it. But, what might be worthwhile, I think, is a time-delayed delete. Move the file to a temp directory for a few minutes and then commit the deletion. That's long enough to catch such a mistake in the command-line, but stays out of the way better than a "trash can" file.