The remote bootstrap script is not part of the exploit at all. It happens in iTerm locally without any ssh session. I just installed iTerm2 on a fresh machine (no shell integration installed), ran the exploit (generated the file with the python script, ran `cat readme.txt` locally), and it worked.
This is explained in the article in the "The core bug" section.
Cannot get it to work. Not worrying about it any more. Still think that the original article is horribly written, now think that their instructions are also.
This is explained in the article in the "The core bug" section.