The scenarios linked to from the GitHub page are not only related because they deal with serverless technologies. They're akin to one another because, in every case, testing was flawed.

In the first, there was no testing, aside from the trivial. Oddly enough, a lack of formal testing is described as being a symptom of not having "a local version to play with." In the second, the test environment was used in production ("So that we didn’t have to wait for the timer to fire “naturally” when we were testing, we were using RunOnStartup = true"). And in the third, there is no test environment.