Karens don’t care if ordinary people have medical emergencies. The most important thing is that they get what they need when they want it. Here is a fine example of how they respond when they suffer the mildest inconvenience. The reality is that there was no way for this poor store worker to win.
It’s impossible to hold in a nosebleed so imagine how Karen would have reacted if she bled in front of her. This is such a ridiculous scenario and the perpetrator had nothing to gain from it. The only explanation is that she was enjoying being a bully (via Reddit).