Hi Dean,
The first answer is, "possibly not", but hte second is, "how much do you care?"
The Installer Cleanup Utility simply convinces the program it's not installed, whether or not it still is. It doesn't actually remove any files. Which is why in some cases, you could go now and reinstall the product (to get a working install) and then uninstall it again (which presumably worked this time).
So long as the product itself uninstalled and all your have left is possibly a few drivers., what you actually have is a bunch of .sys files in your drivers folder which could later be used to install a new tape drive, should you add one.
If you add a tape drive, it will still use the OEM or MS driver by default, so you're not actually doing anything.
The only way that the removed Veritas Device Drivers are still present on your system is if you still have a tape drive, and when you view its properties in Device Manager its driver manufacturer is listed as "Veritas".
If you have this situation, all you really need to do is an "upgrade driver" and then manually install the non-veritas driver.
Otherwise, I suspect you'll be looking at a "more effort than it's worth" situation, where you get a list of 1000 dormant driver files not doing anything, and manually remove them to gain 5MB of drive space.