I don't think the ruling was so much "this is freedom of speech, so it's protected" (though it does seem the defense lawyer tried to argue that) - rather, the laws currently protecting privacy there refer specifically to places where you remove clothes such as bathrooms and changing rooms, so upskirt photos don't actually break the law as it currently exists.
Legally it seems correct: the law prohibiting "covert photography in bathrooms and changing rooms" clearly doesn't apply to upskirt photography in other places, so the people shouting at the court are misguided: this seems to be a matter for the legislature to amend the privacy law to cover this, rather than demand that judges pretend it does already despite saying otherwise.