Brussels is increasingly English-speaking in general, and folks who work in the train areas in particular have to be fully fluent in French, Dutch and English, where the latter is just the default communication choice if you detect someone is not a native Dutch/French speaker. As well the area around the Noordstation is particularly unwise for a tourist to visit for cafés, so it is extra important for them to get across where you ought to go.

An amusing version of this happened to me in Porto recently at a bookshop. Many moons ago I was fluent in Brazilian Portuguese, but today that's retained mostly in reading, I can't speak well nor can I easily follow European Portuguese speakers. I was browsing the Portuguese literature section when the shop keeper asked me question (which I didn't catch), and then upon ascertaining I spoke English she rather forcefully explained where the English section was, but very confusedly watched as I politely kept where I was. To make matters probably more confusing I ended up buying a linguistically avant-garde book that I soon learned really is best suited for native speakers (Guimarães Rosa, the author, is basically a Brazilian James Joyce)