[Volundr]

This is the first I've heard of this, but it hardly seems like the UK press made him do it. The lady asked a question about his achievement and he responded talking about his shirt.

Perhaps he genuinely felt bad about what he (probably unthinkingly) chose to wear, the possible message it sends, and wanted to address it?

[exstudent]

It was a reaction to an article yesterday on The Verge (http://www.theverge.com/2014/11/13/7213819/your-bowling-shir...)

So sadly, it was the US press that made this happen.

[trhway]

American prudes can spoil a party like nobody else, you have to give them that.

[TeMPOraL]

Like /u/exstudent says, it was a reaction to a Verge article and a huge shi(r)tstorm that followed after that, on Twitter and elsewhere. SJWs made the guy completely break down.