1. First, you need to navigate to your hard disk, and locate the Library->Receipts folder. Find the file QuickTime71.pkg, and send that thing to the Trash!
2. Next, since Apple removed the 7.0.1 download, we have to get a newer version, and roll it back. Let's go with 7.0.3 Go here: http://www.apple.com/support/downloads/quicktime703.html
and download that file, and mount the disc image. Do NOT open the package just yet!
3. Now it's time to overwrite that pesky 7.1! Download the most-excellent app "Pacifist" from here: http://www.charlessoft.com/
Pacifist lets us get by that "Apple Installer needs to run a program to let you know you can't install the program you want to install because we assume you're completely stupid" problem.
Open up Pacifist, and click on "Open Package". Navigate to your 7.0.3 installer image, and select the 7.0.3 installer package.
Once Pacifist starts installing the new old QT, whenever it asks you if you want to replace or update a file, always replace it!
When it's finished, reboot!
Throw some money to this guy if you can afford it, this little program has saved lots of lives! I think he only asks for $20.
4. Next grab the 7.0.1 reinstaller for 7.0.3. http://www.apple.com/support/downloads/quicktime701reinstallerforquicktime703.html
Run it as usual, reboot, and you're good to roll!