Yes, "leaving computer science" means that participation rates are going down, that fewer women are choosing it now versus in the recent past. The phrase always meant women as a group are leaving, it never meant that lots of individual women were starting CS careers and then quitting.

> If you look at the most equal and rich countries where women are doing as well or in some areas better than men you don't have many who chooses software development as a career.

That is not true. Participation rates have been very high in some of the countries that are now low. Participation rates in some of those countries are currently high.

You're trying to suggest that women as a group don't want computer science, by their nature as women, but to make that claim you have to deny history and ignore facts.

> It could be just that fewer women want to be software developers and that is all that there is.

The numbers changed a lot, and there is a reason. What you're saying is you don't know the reason, and I agree with you.

> it is also very possible that it [discrimination] does not affect the number of women in tech much at all.

I think it's extremely, extremely unlikely. It's demonstrated that the choices are cultural and not intrinsic to gender. So, your job then is to show that cultural attitudes are not affected by cultural discrimination. You're setting yourself up for an impossible task.