

This only guarantees your WANip:8100 will map to 192.168.0.113:81, and doesn’t address whether or not dns resolution is correct. I would also be weary of using port numbers on wikipedia’s known ports list, as some ISPs will filter those upstream. The last thing is that your router may not want to hairpin that traffic, so if you’re not coming in from the outside it might not be a valid test.
tl;dr he sandbagged the movement when it was beginning to build momentum with a bunch of, what would charitably be called, misunderstandings of the whole point.
It’s covered pretty thoroughly here: https://youtu.be/HIfRLujXtUo?t=1117