Hi Joel,
If the installer isn’t responding to the --help command then there is something more going on that is not the fault of the installer. I would check the md5sum on the installer with a known-working version to make sure that the copy didn’t get corrupted at some point. In the past, there was one time where I worked with a guy for several days trying to figure out what the heck was going on with his environment, but turned out his installer didn’t download correctly because the md5sum’s didn’t match. Once he re-downloaded the installer everything worked fine!
The --help command is one of the most basic commands the installer responds to, if it doesn’t respond to that, then there is more going on. Can you run any other installer/executable on the system? Does the installer have enough memory to function?