Greetings,
I checked out the install log, it would appear the install went fine. Based on what I am seeing, the duplicate entry for 11.0.4202.x is just a registry key that is not getting removed during the migration that is displaying in Add/Remove.
To test this, I would suggest getting a test box that won't matter if the install messes up due to this. Once you have that, try the following:
-Click Start > Run
-Type: regedit
-Navigate to the following keys:
HKEY_CLASSES_ROOT\Installer\Products\
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Installer\Products\
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\Products\
-On each key, highlight it and hit CTRL+F
-Type 11.0.4202 and hit search
-I am sure you will find an entry for this in one of the above keys, when you do delete the main folder that it is under on the left hand side. The folder you delete will be a hexidecimal type folder similar to {A4MSMA-3RVSDV-32GGDSV-325R23G}
After you remove any of these entries you can go to Add/Remove and verify if its there or not. If it is, select it and go to change. You should get an error saying it was already uninstalled and the entry will purge itself.
As far as a more permanent fix I would suggest getting a case opened with Symantec so we can get this information passed over to our engineering team.