"The lady turns over her left foot and the RF to complete the turn. The body should be backing the wall on five the foot should continue turning on six to backing diagnal to the wall."

Yes, which is to say that most of the turn will already be complete before she lowers her heel on step 6, regardless if she chooses to do it in a timely manner (before her feet close) or tries to do it late a result of misunderstanding the technique of this sort of action.

In short, the turn doesn't really complicate the heel lowering at all.

"Where did the Traditional Slip Pivot come from."

It was raised as an example of a step where you do execute substantial turn on a foot as you roll into and through its heel. Although this doesn't happen to any great degree on step 6 of the lady's reverse turn, the point was to demonstrate that it wouldn't be difficult if it did need to happen.

In other words, we're back where we started - this sort of step needs an earlier lowering of the heel than in other types of action, and th presense of turn earlier in the figure in no way complicates that, nor would it even complicate things if the turn were to need to continue during the lowering (not that it does).