Beef between my boyfriend and one of my friends

Some context:

I play DnD with a group that consists of some friends, include said friend and boyfriend. Recently, he has told her she cannot play anymore, which has obviously made her upset. His reasoning was that she not only doesn’t show up most of the time, but when she does, she doesn’t engage with anyone there except her girlfriend. She also made jokes that made other members of the table uncomfortable despite them telling her to stop. When he confronted her, she went on a full blown rant on how he was discriminating against her because of her mental health (I saw the texts.)

Now today, she came up to me and complained she’d been kicked out, not knowing I already knew, but I played it safe and responded like I was hearing this for the first time. She said he kicked her out because she never showed up, but she said that she had told him before hand she’d be absent a lot, and she said he’d just forgotten she’d told him, and that he kicked her out for no reason.

It’s tricky, because I saw the texts, and I know she didn’t tell me the full range of the conversation. On the other hand, I don’t know how I feel about him kicking her out without giving her a chance to change. I’m torn and it feels uncomfortable. Is this my responsibility to get involved in? Do I just remain neutral?