Thanks. Just a quick look through and it makes more sense now. Theres also a few places where you comment saying a borrow occured before the borrow occurs (in others the comment appears afterwards, as I would expect) - i.e. the comments are in the wrong place / inconsistently placed.

Obviously it doesnt affect the output of the code, but as a tutorial its probably better to correct that.

EDIT: further nitpicks, i would advise against calling the borrower the "borrowing owner", and other such terms - owner has a very specific meaning when it comes to memory management, etc.