There are definitely times when breaking a law is safer than following it...in part, because there are some really poor laws on the books in some places. Some states in the U.S. have mandatory bike-lane laws with no exceptions. In many situations, it would be dangerous and irresponsible to obey such a law. Other states require you to give a turn signal continuously for a set distance before a turn or lane change. While communicating clear intentions to other drivers is vital, signaling continuously (leaving only one hand to brake) is often a bad idea.
Thing is, I wouldn't think to use the term "scofflaw" to describe a cyclist who breaks these sorts of laws. A traffic law which mandates blatantly unsafe behavior has no legitimacy in the first place. You may still get a ticket, of course...but that's a different issue, and potentially offers a chance to help change a bad law.