As you say Chesty, the captain can deviate from any rules in the interests of safety. If you consider it necessary to fly inverted under the Golden Gate, you are perfectly entitled to do so. However, you must expect to justify your actions subsequently. Those are the privileges and responsibilities of command. Anyone ignoring ATC instructions has the same requirement to justify. Back in the days when I was young enough to command an airliner, if ATC called "stop" (which they never did) or "Go around" (which they did several times), I always felt they knew better than me what was going on.