Doc to answer your question. The UPHClean msi engine returns a good result (zero) but it doesn't add an entry into add/removes. If one installs it as a user manually (thru the wizard) - an entry is created in add/removes.

If one tries to un-install this "mostly installed version", the msi complains that its not installed (i assume because its not in add/remove).

In terms of the eventlog no - nothing there. We do have the msi log though and reviewing.