Thanks For the Free Time Off!
When it comes to leaving your job for another one, you want to make sure you go about it in a civil and respectful way. Regardless of how badly you might want to leave your current job, it is important to remember and thank them for all of the time you spent working there. That is if they aren’t complete jerks to you in the process…

And seeing as this is how this person was treated whilst they still worked there, it is safe to say that they probably weren’t too concerned about respecting them in a time of sensitivity. Who knows why this person’s manager went off at them for this, but either way, it didn’t matter because they had a plan B.