This bothers me the most about any of it. When you go through such an ordeal, you usually remember even the hardest and smallest detail. It's hard to forget after all. But thing is, they can't recall even the biggest things, and it's so woresome and makes actual victims look like a cry-wolf situation when they come out on these types of platforms.
Why do people come out on twitter or tumblr and the like? Well, I think it stems from the fact, that not much can be done in certain cases. Look back to the Renard/Squishy thing. He had run back off to Canada, no way were they going to extradite him on a small charge like sexual assault, but she was able to run his name through the wring... And luckily, had detailed recallings and multiple witnesses come forward for her. (Her own brother included.)
However, people like this who signal, and scream, "HE HURT ME" without any refute, it makes claims like that weaken.