Cool. :D
I don't have the book handy right now but have read it several times along with Total Archery.
What I am writing is from memory (which may not be so good).
I think that what Lee is referring to is maybe a little different then my statement.
This is what I interpret from Lee's single statement mentioned:
Often times an archer will start the shot sequence with a correct deep hook, but while drawing, loading, or anchoring, may start to lose the shape of the original correct hook. Could happen for a number of reasons including and most common in the "transfer" step. It could also unravel just by the increased poundage of the bow while drawing. A lot of times an archer may misconstrue the transfer to mean completely transfer all tension from all parts of the hands arms etc. to the back. However, it is important that the hook be maintained throughout the entire shot sequence. What I believe Lee is saying is that he hears coaches say "keep the hook" instruction while seeing the archer starting to lose the original hook position. This could be easily mistaken by the archer (again usually beginner) to mean change the string position in the fingers instead of curl to fingers back to the original position to maintain the correct hook. A more elite archer, I am sure would have to let up on the shot and start from scratch instead of just curling the fingers back into the correct position. I think Lee is using this as an example to a coach on how a miscommunication can easily occur between the coach and student if the coach does not fully explain in detail (and hopefully demonstrate) what he means. Coaches often think that a student understands exactly what the coach is trying to convey, but that is not always the case.