I believe his last sentence is in error. 8-7-E is in regard to assisting a runner during live ball in which case the ball remains live and the runner is simply called out. The exception is also in relation to assisting a runner during a live ball, but, it is referencing what happens if that assistance is on a runner who has passed the plate and is then assisted. In that case the ball now becomes dead and would be the only situation where physical assistance is a dead ball.