To those who know who they are:
He should have reported the racism sooner .... in the UK the climate is very supportive if/when such reports are made .... so if you are experiencing this - dont hesitate - report if you consider that you are being harassed and abused.
Dont curl up into a ball ... dont feel sorry for yourself ... dont get super angry or be otherwise too emotional (as this guy seems have done) .... take effective action ... and keep it moving.
I'm personally an incredibly thick skinned person, and I used to think like that not just in terms of racist remarks, but also bullying and insults (coming from a minority background, and being overweight growing up). I used to wonder why words affect others so much, because they don't affect me in the slightest. If I got some, I'd be happy to dish some back, no problem. So why don't others do the same? Confounded me all through Jr School, High School, College, and even some early jobs.
It wasn't until I became a people manager in my career, that I started understanding how and why people didn't behave, react, or didn't react like I did. In a workplace, especially, someone who feels victimized can feel like their job is at stake if they complain because of the company culture. There are people who feel like if they don't go along with the things that are being said to them, it would make things worse. Maybe people won't cooperate with them to get their own work done. Maybe they won't be able to make friends, or socialize AT ALL. Maybe it triggers their own anxiety in a way that affects their own performance.
People come from different backgrounds, different upbringings, they could have grown up going through either physical or mental abuse, and be conditioned to others treating them this way. In that situation, it's really difficult for these people to have the confidence or courage to speak out, even to the appropriate channels, to have these issues investigated.
There are so many factors, that I've now realised that different people are built their own way. Your advice may work for a few people, who just need a slight push in the right direction to make the changes needed to improve their work life, however, not everyone is equipped to deal with things in that way, and it's a lot harder for them to come to terms with it and deal with it. Unfortunately, there isn't a blanket solution to issues like this for everyone.