I guess the "or should have known" is a key part here. In most cases where the person didn't know, they should have. The difference here being that they _did_ k

I guess the "or should have known" is a key part here. In most cases where the person didn't know, they should have. The difference here being that they _did_ know that they _weren't_, and they had probably taken reasonable steps to ensure that they weren't breaking the law.