On reflection I was mistaking the situation for turning 90 degrees into column (I don't think I've seen anyone trying to take multiple moves to form columns here - the 90 deg turn is the normal method for forming columns in these parts).
when advancing and forming a column the wording is pretty clear and I agree with Foxgom - if you're taking multiple moves to form the column they you all have to end facing the same way until the column is completely formed.
However if, at any stage, you choose to seperate off those elementsthat are already in column and leave the rest behind then you're free to wheel as you want.
I think discussion about Phil's "intent" just confuses the issue - the wording is clear and should be applied without trying to 2nd guess that it might bean something other than it does.