Still about the W

[RosaLinda]

How funny/sad SA, that your W can identify the problems with her SIL, but does not recognize the same things about herself. I guess people are sort of blind about themselves. I'd like to know how others view me, would you? I already know what my H thinks of me LOL! 

My hospital paid a consulting firm a lot of money to give us lessons on being polite, really is what they boiled down to. I was flabbergasted when the nastiest, most angry, belligerent employee in the place seriously told me SHE doesn't need lessons, she is always charming

It sounds like your BIL is doing some good DBing!
1. "her brother is oddly detached, as if he is watching this from the sidelines."
2. "it's been about 3 years now, and her brother is just patiently waiting it out because he's seen the divorce of many of his friends and he doesn't want to go that route."
3. "her brother doesn't think he has options, and it makes it easier for him to be patient."

have you spoken to him?