She's been diagnosed as bpd and BP type ii. We have this mutual friend and they recently had a falling out. From my point of view, they're both wrong but the situation could have been reconciled. My roommate doesn't want anything to do with this mutual friend and a lot of their situation has pushed back on me so now I'm losing multiple people in my life over this and my roommate is very apathetic to my feelings. Do you think my roommate is splitting on our mutual friend?  Is there a way to tell if she is? And is there any productive way to fix this? 

This mutual friend did do multiple wrong things but is a good person and my roommate has a separate friend that is arguably a bad person who has done way worse things that she's forgiven. 