Re: rollout/shoulder roll... you'd only do it if you're already going forward and down, but nage hasn't quite got your arm straight or the lock on, or both. But I wouldn't try it if the arm/shoulder is fully locked - not unless you want a dislocated shoulder. Basically, you roll over your shoulder - like how you would do a backward roll over your shoulder to get up, except you're going forwards in a roll but unfold onto the mat.
Anne Marie, I finally found a decent video....
As you can see, when correctly applied with timing, you won't have time to do a rollout, you'd just drop.