No, I think what happened is that OneDrive overwrote the local db with a version from the cloud that was several seconds older, corrupting everything. Or maybe it just overwrote the lock file? I'm not completely sure. Whatever it was, it appears that OneDrive replace a newer version of the db with an older or partial/corrupted one from a prior sync.

I should mention that I was able to repeat the corrupting problem reliably. The problem disappeared when I moved to a working directory that was not monitored by OneDrive.

I was setting up a very simple db from a few CSV files, for use in a data science exercise for a course. There was nothing interesting happening in my code at all-- maybe a simple table join sql query, at most.