He literally said it during the interview this article is about.
And I quote:
I did something wrong 10 years ago. I have to take that. But hurting the people around me, whether it be Matthew (his teammate) or my wife or my child… that goes too far for me.
And from a previous interview in 2018 (in Dutch): nos.nl/l/2240281
I did what I did. I can’t reverse it, so I’ll have to live with the consequences. You may judge me, of course. It is the biggest mistake of my life.