All the cited science in the manifesto is irrelevant in my opinion. As an engineer you work with other people. You probably spend 40 or 50 hours a week with them. They may or may not become your friends, but they will have a huge impact on your life, and you on theirs. Many of these people will be women. They are REAL people that you interact with everyday. What he did when he decided to share this manifesto at work is show that he thinks of these women as statistics, and that on average they are not as capable as he is. He has turned the women he works with everyday into a technical problem that he can solve with his intellect. That is incredibly insulting! He's shown an incredible lack of empathy and understanding towards the women he works with. He's turned them into numbers. He's shown he does not care about them as individuals. This is absolutely unforgivable.
If he had simply released this as a research project or something on the internet then it wouldn't be a problem. But he didn't do that. He didn't make a distinction between the general population and the women he works with. He shared it at work.