Thanks for the nice article. The SQLite docs that explain this bug are emphatic about how utterly rare, even irreproducible it is. How, then, was it found, one wonders?
It's in Chrome, Firefox, Safari, Windows 10, macOS because it efficiently solves a huge number of use cases while giving plenty of headroom for flexible querying.
If you have data more complicated than a single CSV or tab-separated text file that you will only ever process in sequential order, and you don't need inter-process interaction, you should be asking why not use SQLite.
sqlite is useful everywhere CSV files are useful but you'd like them to have more data integrity and faster updates. sqlite can replace some uses of MySQL, but more commonly it replaces fopen. https://sqlite.org/whentouse.html
My guess is that they noticed something was not quite right when inspecting the code and then tested their hypothesis manually to see if it was actually a real bug.
Something similar happened to me when I was working on some code that should clear the state and, by inspection, I noticed some field was not properly cleared under specific circumstances. Then I tested the hypothesis and indeed found a bug. Sometimes intuition and guessing is what it takes.
We should probably blog about it.