Here's my take: If you're going to openly defy authority, then you better have clear Biblical authority, and be able to articulate why disobedience is absolutely necessary. And that means more than just reading and coming to a conclusion. I'd argue that a consensus is necessary, i.e. talking to other Christians, and elders.
Ooof. I wonder what Martin Luther would've said about that as he was hammering onto a door.
Ok, a bit more seriously. In the Catholic tradition (and probably others, I just don't want to be read to be speaking on behalf of others), there's an emphasis on the examination of conscience. If done properly, through prayer and a true willingness to obey God's direction, I don't think a consensus among others is even a factor.
If called, an individual can act pursuant to God's "request" in a way that cuts against the consensus. There can even be a genuine disagreement among parties who have both discerned God's will through an examination of conscience. None of us know God's plan completely. The best we can hope for (IMHO) is to find His path for us individually.
There have been times that I have stood in opposition to "higher ranking" Catholics. It has been after much prayerful discernment about my role the matter. I don't pretend to know if I was right - I won't find that out until later. I just know that I believe my choices were consistent with what God was calling me to do.
Keep in mind, because slavery is kinda sorta approved in the Bible, there were a significant number of Christians who opposed abolition, too. Depending on geography, a consensus against slavery was not a certainty.