Brother dealing with DV case at work

He needs to develop professional boundaries, he should be dealing with it in work hours for a start and leaning into support from HR and occupational health.

He really needs to speak to HR. He is blurring professional and personal boundary lines here and quite honestly this can backfire. He can't "fix" this situation and it's actually not a good idea for him as an employer rep to get too involved. Yes there's a duty of care but being too involved means that he's potentially then setting himself up for trouble if things go in a difficult direction.
I'd just suggest to him that he speaks to HR and asks them to get involved rather than him

*However, this woman is no wallflower, she perpetuates situations. Argues and ‘winds up’ her partner knowing how things will end. It’s an awful situation.

The woman sits and goads her partner, not that DV is in any way OK, but she literally winds him up to get a reaction, instead of just leaving the guy.*

I know I'm missing the point but how do you know this? Have you been there when it happens?

If it's the woman saying she does this, it might not be true. It's probably what her abuser is telling her she does and she's so ingrained in the abuse this is what she believes.

He sounds as if he enjoys being part of this tedious drama, and is therefore lacking something in his life.

As a former victim of DV, and one who has done a lot of work on myself and some volunteering to help others in groups, talks etc, I agree that however kind and well meaning, he is not qualified to help her and the advice to scale this up to the management IS the right way to go. The best thing he can do to help is to get help from the company to help her. He does need to detach somewhat, but I can fully understand how he would not find that easy (as I wouldn't either)

Please try not to be so dismissive of a person who is in an awful situation. You said yourself, she thinks this is normal in some small part of her head. This is not her fault. her inability to see the right path in all this is also not her fault. the 'right' path feels alien to her.

Until you have felt the dark evil cloud of simmering brooding tension from an abuser you will never understand how sometimes you wish to get it over and done with. there is a nice to nasty cycle and it loops round and around.

His management needs to help him put effective processes and boundaries in place. He will end up utterly burnt out otherwise.

Your brother needs to have a firm talk with this woman. He must tell her he will not be involved in her dramas anymore. He has offered help, she has refused. Also as pps have said, he needs to speak to HR about it.

He needs to take a big step back . She is not his problem and he should not feel guilty about the situation she has creates for herself. Given the description of her behaviour maybe it's her that is The abusive partner tbh

He’s not helping her - it sounds like he might even be reinforcing the situation unwittingly, he’s been given a “role” in the drama. He needs support from managers/HR and to be very clear and firm that he can offer x support during x time, not to contact him at all hours.

He's not being lovely at all. If I was his wife I'd be absolutely fuming that he's prioritising this woman over his own family. Is he aware he's jeopardising his marriage for the sake of white knighting for this woman?

He needs to take a huge step back and stop getting involved in her drama. It's very sad what she's going through, but she needs professional help, not an emotional pack mule to carry it all for her.

He needs to block her so she can't be contacting him at home day and night and set some firm professional boundaries with her now. Absolutely no good can come from this level of entanglement with an employee, if he's her manager he's also risking his job by getting this over involved. He needs to speak to HR for advice on how to proceed.

He needs to speak to HR.
They will have policies in place to safeguard him, and ensure duty of care for both.

Then as hard as it may be he needs to step back and follow the policy. If that means signposting to various organisations - that’s what he does. If it’s calling the police, that’s what he does.

She may not be able break the circle, but your brother can for the parts he’s responsible for.

I think that he needs to tell her as a manager his duty of cate is to involve the police whenever she contacts him. Ask him would he want to admit to not doing that when giving evidence at court? He should be asking HR for advice.

Would it help for him to read around DV so he realises that the time has passed for her to leave? What does he say when his partner points out that he's prioritising a colleague over them? He needs to get out of saviour mode because it isn't going to happen.

Oh dear. People can only be helped when they come to the realisation that they need to leave the situation. Tell him to fall back until she can see this. Unfortunate but...