It's not piped to a shell, but to the tar program with specific parameters to directly unpack the tar.
You're still installing the program directly from github of course, instead of a source where hopefully a third party has also looked at it (like a package repository). But this is a lot better than the curl | sh pattern.
You're still installing the program directly from github of course, instead of a source where hopefully a third party has also looked at it (like a package repository). But this is a lot better than the curl | sh pattern.