He (the former PM, not the current one) came out of some building on some official occasion, I want to say it was actually our national holiday. Now, you have to keep in mind that he is a native Dutch speaker - actually bilingual, his father spoke French, but in his daily life he speaks Dutch and he definitely considers himself part of that community. So then a Francophone journalist comes up to him and, considering the former PM's reputation for being kind of anti-Francophone (despite his family), kind of provokes him by inviting him (in French) to sing the national anthem. Admittedly, singing the national anthem in French would not be something that he'd have done very often, he'd always have sung it in Dutch presumably. Nevertheless, it was rather embarrassing when he began to sing the first few lines of La Marseillaise, the French national anthem. I dare say a lot of Flemings might have done the same - we've heard that one more often and know it better than we do the French version of our own national anthem, and there is a certain similarity in the tune in the opening lines, so it's an easy mistake to make - but then the rest of us weren't PM.

Suffice to say, his reputation among the Francophones went even lower and never quite recovered.