Making friends as an adult is not as easy as it once was when you were in school. We grow up and get jobs and start to develop different kinds of relationships, professional ones. And you can't treat your coworkers like you would everyone else. You have to set different boundaries with them. This isn't always easy to do, though. Sometimes someone crosses your boundaries, and you have to sit back and deal with the consequences. You have to put them in their place, but that is easier said than done. This story between a coworker and their new colleague was a little bit alarming in this way.
Texting allows us to reach each other all the time. You can send a text message without any warning, and without the consent of the other person. It's the lingua franca of most relationships now, and that means that we all take it for granted. But there are ways to text in an appropriate manner and ways to text in an inappropriate manner, especially with your coworkers. When you're excited, you might fire off a bunch of texts to a friend. But this is fine to do only because you have an established relationship with them already. You're not asking them too much, because they're your friend. But what happens if they're not your friend? That's what was happening here.