True he doesn't use manchester encoding and it does work without manchester encoding. But what the project is doing is so very simple and error tolerant, it doesn't need error correction and just ignores errors.
I'm only saying that you'd be doing yourself a big favor by learning what manchester encoding is and why it works the way it does, and then apply those principles to your project, even if it is something as simple as turning a light on and off...or whatever.
I can guarantee you that it will come in handy in the future if/when you actually try to send data packets back and forth and need reliability. You know how it is, projects get more and more complicated!
JDG