> It is enough to say absolutely nothing, and request the government to prove its case.
Only in criminal contexts. In civil contexts your silence can absolutely be an adverse inference. Usually these red-light cameras are civil penalties, not criminal (fines with no points). The judge here seems to be saying that these are "quasi-criminal" because, uhh, I guess there are penalties.
In some ways the government bringing civil charges against you is rather bullshitty and in many ways can be used against you in violation of your constitutional rights. Hence is the most likely reason the judge is calling it quasi-criminal.
Right, in effect the Judge ruled that while the state _calls_ it a civil matter, they treat it basically the same as any other criminal matter and therefore it is in fact a criminal matter. As we all know, a rose by any other name would smell as sweet.