Yeah, I think this is trying to take things further that how really were; Especially when you're citing the same event where Rin clearly says that she can look past on those things because she know the nature of Molly actions were never with the intention on doing harm or almost-raping anyone, which is basically what you are suggesting.
¿What Molly did was bad? Yeah, of course, I never tried to say the opposite, Molly screwed up, and Rin had even the right to be mad and cut ties unilaterally for those actions, but what pisses Rin and what actually led her to cut ties with Molly, as you cited, was the fact that Molly disregarded his feelings and acted still knowing that she was falling for Otoha.
Now, what I'm saying actually is what Rin herself said
This time Rin were in Chika's shoes, with the exception that the other girl was a real close friend of her, and I think a good friend would have at least tried to hear what the other had to say, even if the answer she would have given to Molly wasn't the one she was expecting
C'mon, during a lot of events before the beach trip Molly was acting weird/sad and basically everyone noted that, obviously Rin noticed too, with the difference she did know the reason, no one is obligated to take responsability for how other people feels, but is your friend right there who's suffering, seriously you can tell me that you're seeing your friend having a bad time for months and that you're not going to do anything despite knowing the reason? Show some empathy!
And
AlthoughI wouldn't say that that was worse, what Rin did was bad too, Molly hurt Rin, and Rin hurt Molly and she knew, but Molly tried to reach Rin, Molly was worried about her friend, about the things that happened, Molly tried to do something about Rin feelings; What did Rin do? Nothing
There's somehing that is called emotional responsibility, and Rin doesn't have any.
As I said, Chika did better for Rin than what Rin did for Molly, and Chika wasn't even Rin's friend
pd: yeah, windows not activated
not my pc