I got caught by this one as well. Technically, I should most definitely have gone with "mine", but to us these both mean the same thing. So, it is not surprising that we were caught by this. Dutch is so close to English that there is often more than one way to say it in Dutch as well and we must be careful to find the exact correspondence, more so than with other languages.
I get this wrong every time during the listening exercise because it sounds like the female voice says, "Welke boterhammen zijn voor mij?"
In conversation it likely wouldn't matter because the meanings are quite close, but when I have to type exactly what I hear and what I hear is "voor" and not "van" it can be frustrating.
Could be my ears, but I am wearing my hearing aids.