Author of the article here. I am surprised to see the post was submitted and made it to the front page! Happy to answer any questions
Is this an allusion?
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.
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.