if the FL just came out and said she was his childhood friend and basically lover that died in that accident she would seem like a crazy person to him and that would cause so many problems not to mention there's the off chance he might call the police on her so no it's not as simple as her...
the FL is just being an asshole and bully and since mentally she is an adult this makes it even worse but most people won't see it that way since most people at least to me when reading manga/webtoon tend to turn their brain and morals off and let their biasness get in their way of being logical