Speaking directly to the arrest, if the book did not contain images involving children, it's not child pornography in Florida. Hence, the obscenity charge. If the obscenity charge is judged based on Florida's track record for enforcing that particular law, it may not stick. Even some mainstream romance novels violate FL's obscenity law, and online retailers and others violate the law on a daily basis. I lived there for over a year, and I guarantee I received material that is "obscene" by their definition, even though the books I received were fairly tame.
Link:Applicable Florida statutes