do they need to resolve those issues by themselves? yes
did she need to spread the word about it? absolutely not
the reason why she is so upset of being groped it's because of previous sex abuse experience. being touched without permission makes her feel defenseless, like a fish on the ground. it is natural that nishimikan would feel very scared towards renard, because he touched her many times in her sleep without her permission.
when i read the whole deal about nishimikan the first thought that popped in my head was "oh, poor girl", but was there anything i could do about it? no. and neither the other people who read it could help her in any way (unless they stalk renard and kill him, but that's another story).
so why did she post it in anyway? i like to think of it as a cry of desperate help. when someone is desperate enough to get out of a situation, they'll end up doing very idiotic things, like talking about your own (very serious) personal issues about your boyfriend, even though she perfectly know the world is not obliged to care, unless it's tumblr.
tumblr is ridden by radical feminists and every type of female that hates the male sex. what nishimikan did was a smart move: she posted a rape accuse in a website like tumblr, because its bloggers will always give a shit about you if you're a "rape survivor" (and if you are not, you might as well kill yourself, you cishet scum). but then again, can these radfem do anything about it? no.
tldr; renard may be a scumbag, but posting it around won't help her, nor him.