Well, it turns out that I have to correct my original post. The installation actually succeeded. I find it unusual that the installation script provided no completion status of any kind.
I attempted the installation on a different machine this morning, again saw no completion status and just happened to see that an icon for Illustrator had been added to the Start menu. I checked with the user on whose machine I had performed the installation earlier and she confirmed that Illustrator is, in fact, installed and working.