It's not just the trans flag issue but the behaviour on social media. Every time Stock or other feminist academics like Selina Todd were in the news for some no-platforming, cancellation or other attack by students or academics, Phipps and colleagues at Sussex and other universities would do these passive aggressive "My support for trans students today", "She who claims to be cancelled gets platformed in the press" tweets which they'd all share and like, along with various nasty comments.
This was happening at a time when multiple female academics were prevented from doing the core elements of their jobs. Threatened, intimidated, no-platformed, had talks cancelled, assaults happening at talks they'd organise or be involved in, bomb threats, Selina Todd needing body guards, Stock needing security equipment installed, students circulating posters with weapons on them. That @devorah thinks this is some kind of comparable situation to academics saying "women have rights based on our sex and this has implications for law and policy" being upsetting to trans activists is horrendous. The academics mistreating Stock seem like really unpleasant types and it was seeing their bullying behaviour that first led me to find out about GC feminism.
Phipps was also frequently tweeting some racist, classist assertions that GC feminism is for middle class white, women but has never backed that up with any data. She trained as a social scientist, so you'd think she might be able to present some surveys or empirical data for her claims.
If she really believes that women from ethnic minorities in the UK are somehow more okay with being undressed around or being imprisoned with bepenised people, than white women, then she should prove it. If she thinks working class women have some kind of invisible shield that makes us impervious to fear of male sexual violence then she should present the data. Instead she constantly smeared feminists and ignored and elided all the BEM and/or working class women who are involved in GC feminism.
When Kathleen Stock and others like Selina Todd and Julie Bindel offered to sit down and discuss or debate the issues with Phipps, Phipps either ignored them or did the whole "I won't debate trans lives" schtick. She wasn't being asked to "debate trans lives" she was asked to discuss conflicts between sex and gender which she refuses to acknowledge even though there is plenty of legal evidence that those conflicts exist.