Yes depending on a new file created after the backup would be operator error. If it is habitual I would call it an undocumented procedural error.
The problem is when the operator is a part of the OS. You can’t eliminate that on a running system, and attempting backups on a running system without knowing the guarantees of running software is the error.
That is what we get when we have what used to be called mainframe scaled computers in the palms of our hands - and the untrained Gen-Z users who operate them. Way back then we knew the guarantees of running software and a backup at the same time. (It was printed in the manuals.)
I’ll let you have the last word.
1 Like
In the first place i thought about a mysql or mariadb Database and known documented backups, as described via how-to. Or if you try to cp -a one File. Like you have closed the database or Program or wrote a backup script as Init or Shutdown progress. This way you have one after you shutdown your phone. For example.
However like your post and discussion for some important knowledge about computer systems and failed backups 
Edit: Tracy for that the Gen-Z have emerged the a.i. to understand that fuzzy stuff in the first place and can self solve issues about… just kidding.