This is exactly why "hate speech" laws are so dangerous. It gives carte blanche to the government to go after anyone who says anything any one person (or the government itself) might find offensive.
I hope this case is appealled, and the law thoroughly weighed against human rights.
One of the nice things about being able to ask for a trial by jury is that jury nullification can help ensure that laws aren't abused even when judges are perfectly willing to "make examples" of people
If you think any single example of a law being applied in a manner that is technically defensible but (arguably) morally wrong should rule out an entire category of laws - you'd have no laws left.
My guess is that most laws are occasionally abused. The trick is to distinguish between those laws that invite it and those that don't.