In hiring decisions there is often an unconscious bias towards "people like us" ("us" being the managers responsible for choosing a candidate).
In areas already dominated by men that's likely to result in new hires being men, which is the focus of this article regarding certain kinds of IT job. However, where women call the shots, it's similarly possible for them to exhibit a bias in favour of female employees. It's likely that hiring bias perpetuates a lack of diversity in a number of industries.
There is currently a lot of research into this phenomenon in order to understand it better and figure out ways to counteract it. It's fair enough to point out that the bias can cut both ways and, at the same time, it's important to remember that male-dominated jobs tend to be better paid: exclusion of women from male-dominated jobs tends to disadvantage them more than it disadvantages the men excluded from female-dominated jobs. Not saying that hiring bias against men (or indeed anyone) is OK, just that the impact is not necessarily the same.
For some pay statistics, see here:
For example, an average female "IT user support technician" is paid 15.5% less than her male counterparts (women hold 26% of those jobs), whereas a male in a "secretarial & related occupation" is paid 7.5% than his female counterparts (women hold 92% of those jobs). But no prizes for guessing which type of role has higher average hourly pay.
(I apologise, without knowing the specifics of the assistant role mentioned here, I have assumed it to be a secretarial or related role but feel free to check the link for the specific role the Zimbabwean candidate applied for and let us know the comparison)
Different types of discrimination also combine to affect people in multiple minority groups worse (where "minority" can mean "minority within the employee population for that job role"). It sounds like the Zimbabwean candidate in this example most likely lost out due to his nationality and gender. Tackling these issues goes to the heart of some very deep-rooted assumptions and unconscious behaviours.
As a white British man with a degree, I am fortunate to have so many good career choices available to me here in the UK, so I don't find it very concerning that a small number of lower-paid jobs would be willing to overlook me because I am still in a privileged position overall. I'm not trying to brag, just pointing out that I'm somewhat aware of my own privilege and that a similar awareness would benefit some of my colleagues too, especially when considering what we can do to make a positive difference to our job culture.
To be clear, I would like men and women (all humans, really) to have the same opportunities to work in whichever job they prefer and to be paid according to their skills and ability to do the role.
Regarding the specifics of the article, I'd like to help make things better for women in IT and would appreciate some advice on how best to do so from within a technical role that doesn't involve hiring people. I've worked alongside a small number of brilliant women and enjoy working with a variety of people to get different ideas and perspectives. I'm not sure how things are going to improve from where we are now but it's a good debate to have and I enjoyed reading this article.