I think if I were representing the two Independent labs involved in the sex tests on these athletes, and our professional integrity and accuracy were being decried, I'd be considering legal action.
I don't think anyone from either athlete's team has said the results are wrong. Both athletes accepted the results and subsequent bans, despite being offered full support to appeal to CAS.
I'm pretty sure that implies these 2 are indeed XY individuals, both have been through male puberty and neither should ever be eligible for XX events.
I'm not sure who Khelif is thinking of suing, nor why (seems deeply stupid to me) but if it goes ahead, I guess they'll have to prove, via tests, that the "they're XY" statements are false.
I'd like to see that.
It does make me question why it's important now but not important enough to appeal 2 years ago. Is there money riding on it? Sponsorship? Ad revenue? Or just a thwarted XY athlete not receiving the adulation the XY athlete feels is the XY athlete's due? A hissy fit, in other words.