Hmm strange there is nothing that should have messed up the file permissions like that, looking in the script. Did you run it as osmc user in the owmc user home folder?
Just ran it on my system without errors, but i found a weakness in the script, if you had downloaded the netflix_repo.zip once it farks up.
Changed that behavior, and if you delete the last downloaded netflix_prep_install.sh, and download it again and run it, it should work, the problem i saw was that i renamed the download, but never the “check for older version”.
Thanks again @AndersG