That just doesn't sound reasonable. University students, to me should be a full-time focus, also very often have one or multiple part-time jobs or even a full-time job while attending classes and doing their school work. Surely being a judge doesn't take 100% of someone's time, and this is also a topic likely close to the commenter. Also, did you look at the date of his tourism website post anyhow?
Speaking only for myself, obviously, I don't find the argument itself to be particularly interesting, but I do find it interesting to find a Brazilian judge posting it on HN, just because that's really unexpected to me. If it's all fake, then the comment ceases to be interesting at all.
My point is that you have nothing to gain by calling into question the title. You give people the benefit of the doubt because that's the way to maintain civil discourse.