You can check for a twisted limb pretty easy by having a buddy watch you draw. However when you do this test make sure only the palm/thumb web of your hand is touching the grip; don't wrap your fingers around the riser. I've seen many guys with a little too much finger pressure on the riser turn their wrist in slightly as they draw, the result being the limbs have no choice but to draw crooked. The limbs are meant to come back on a plane parallel to the riser. Highly stressed, high performance limbs like a BW are more susceptible to this, often called torquing as you described in your opening post. Once they twist they're more likely to twist again, but you can "bump" this out of the limb pretty easy and it should stay true.