There's a little wiggle room.
For one thing, we don't know the details of New Troy's legal system. Local laws might be a little different than they are elsewhere.
The other trick is that Superman's legal status is, well, if you'll pardon the expression... up in the air. He is, quite literally, an illegal alien. But he's also been given some official recognition, like getting the "key to the city." He might, in a sense, be eligible for diplomatic immunity. Or you could argue that, as a non-citizen of indeterminate status, he needs to be tried at the federal rather than local level.
Or maybe the judge herself, sympathetic as she was to Superman (and skeptical of the claims that led to the injunction) could be persuaded to be lenient.
Paul
