Re: Bending the wrist and tailing loops
There's not a disconnect between the statement that wrist bend can cause open loops and the statement that wrist bend can cause tailing loops. Open loops don't prevent tailing loops; although they can cut down on them.
The mechanics of the casting stroke are what is important.
Wrist bend at the end of either the forward or back cast can, definitely, open up your loops, because the path that the rod tip is following is changing from both a forward and back perspective and an up and down perspective. It's the relative up and down perspective the gives you the open loop. Remember, the line will follow the rod tip; it goes where the rod tip points.
A tailing loop develops when two things happen; 1. the plane of the rod tip drops (gets lower; which a wrist bend at the end of your casting stroke will definitely do for you) and 2. you delay your casting stroke (you're late starting either your forward or back cast.). Both of these things can give you a tailing loop; but they usually happen together; you lower the plane of your rod tip and you're late on your casting stroke.
The right timing on your casting stroke can make up for a change in your rod tip height; because the momentum created by proper timing takes the tailing loop out of your stroke before it becomes a problem (you don't notice it). If you accelerate your stroke smoothly from the start to the end; speeding up as you go, tailing loops will very seldomly appear. If you accelerate abruptly (with a jerk) and maintain or decease the speed of your stroke as you proceed, you will find the tailing loop and the tangles that it creates with your leader/line.
An open loop is not the opposite of a tailing loop; they're two separate effects, both derived from the mechanics of your casting stroke.