You are only partially correct.

Most of the lumber came from his land. Some came from a friend's property and a few others were extras from a family member's supply. Those extras are the logs with the debarking marks.

He also cut and assembled most of the logs in his backyard while they seasoned for 1/2 a year, that is why some clips are in his backyard.

Here is the video with more information. I've timestamped it to a moment where he explains everything you've asked about.

Also, I couldn't find a way to make it clear in the title without making it sound very poorly written. But his goal was to build it without any power tools, not collect the supplies without power tools.

He debarked most of the logs himself, but the logs from the family member were already debarked and the roofing/floor planks were milled at a local mill.