If curl loses connection to the source website while downloading the script, then partially downloaded script will be executed, no matter what. This is a main drawback of curl-to-shell piping approach, and the original article is missing it entirely.
A common solution is to wrap all code within a function. This way nothing gets executed until the last line, the one that calls the function, is executed.
Yeah "it will happen anyway" misses the point that curl will notify you of the failed download before you run it, whereas piping it to sh will immediately run it
Is that really much of a problem? I can't remember the last time I had a download fail part the way through and they are usually much bigger than a bootstrapping script.
As was pointed out both in the article and the comments here, this is easily addressed by wrapping everything in a function (or subshell, for that matter).
