I agree with this. Although the wiring shown is not "technically" correct according to the book, the book is often thrown out when you are dealing with real wiring situations. None of us can know the real reason that he reversed directions, but look into the trees of any professional yard in any country and you will find many situations that do not follow the rules.
To be clear, though, I also do not promote wiring anarchy. The "rules" are there because that is what usually works. but they are not laws.
Basically, we followed these rules for wiring in Michael's yard:
1. Don't Cross wires- You remove wires when they need to be removed and not all at the same time. If you cross them, you will not be able to remove the lower wire without removing the one that is crossed over. Also, when you cross, the point at which they cross tends to dig into the branch worse.
2. Use the correct gauge of wire to do what needs to be done with the branch/trunk that you are wiring. This is an absolute. Miss this one and you rewire the tree.
3. Do not change spiral directions. This makes sense because of how anchoring and bending with the wire works. There were situations that warranted changing directions, but it had to be intentional.
4. Use as little wire as needed to get the job done. Overwiring= waste of time and wire. Underwiring= you cannot accomplish what you wired to accomplish. Luckily you can always add more wire. Just try to not have to do that while you teacher "patiently" watches over your shoulder for you to finish.