Rehearse, do not scrutinise

Not undoable: confirm first, every time.
Where the whole-file write starts.

Not more attention at the end: a copy of the file, made before the write.

Free to undo: run unattended.
Where the write ends up, with its copy.

The bottom row becomes the top row. The copy removes the possibility rather than improving your odds.

A copy first Rehearse, do not scrutinise Band What it changes Action without a copy Whole-file write copy, made first Not more attention at the end A copy of the file before it Bottom row into the top row A rehearsal beats checking the real thing harder Removes the possibility rather than improving your odds