Looking through the judgment, and here's the definition of gender identity in the Sex Discrimination Act: "gender identity means the gender-related identity, appearance or mannerisms or other gender-related characteristics of a person (whether by way of medical intervention or not), with or without regard to the person’s designated sex at birth." Note that 'gender' hasn't been defined.The introduction of 'gender identity' as a protected characteristic has entirely confused and screwed up the sex discrimination act.
Some thoughts on key bits:
Paras 55 to 57 say sex is not confined to a biological concept, nor is it binary. Sex can be changed. Being 'non binary' is a separate sex from being male or female. Sex can also encompass legal sex, how a person presents themselves, and how they are recognised socially. This shows how crucial it is to stand firm on the concept of biological sex, and to get rid of legal sex fictions.
Para 74, the judge says that gender identity encompasses transgender people and also cisgender people. Given that transgender people are already protected in law, it's unclear why they need an additional 'gender identity' protected characteristic. This also leads to the possibility that a service could be provided for 'cisgender' women only
Para 76 points out that you cannot evade a claim of gender identity discrimination by saying you were discriminating on the basis of sex. Given that sex and gender identity overlap to such a degree, this means it is no longer possible to exclude males from female spaces on the basis that they are male. Their gender identity also has to be taken into account.
78 says that if Grover had known that Tickle had a 'female gender identity' but 'dismissed its legitimacy' and then excluded him from the app this would be direct discrimination on the basis of gender identity. This means that any male can just say 'I have a female gender identity', and if he is then rejected from a service direct discrimination is made out. There is no test proposed for how you decide the 'legitimacy' of someone's gender identity.
Para 85, Grover said that the app should be excused as a special measure aiming to achieve equality between men and women. This argument would have succeeded if Tickle was a cisgender man who was banned from the app. However, Tickle is a man with a female gender identity so the argument doesn't work . Para 86 says that special measures to achieve equality between men and women (in effect, female only spaces) cannot be used as a shield against discrimination on the basis of gender identity. Given that any man can claim to have a female identity, this makes it practically impossible to have any single sex spaces in Australian law.
Para 131 says that it is direct discrimination to deny there is a legitimate distinction between transgender women and cisgender men. The judge seems disappointed that the cross examination didn't delve deep enough to establish direct discrimination.
134, the condition of applicants needing to 'appear to be cisgender females' indirectly discriminates against transgender women because they appear to be male. This means if you want to exclude a man, you have to first check if he has a female gender identity. if he does, you cannot exclude.
In short, the judge did appear to be fettered by the law before him. This mess can only be fixed by a higher court sorting this out or legislative changes. But the effect is that women cannot discriminate against and exclude males with female identities without committing unlawful discrimination.