Can't install to folder that is only writeable by Administrator

Steps to reproduce:
Download Creator 2.8 rc candidate package 528 from http://builds.qt-project.org/view/Qt%20Creator/job/qt-creator-windows-snapshot/

Make sure that C:\Qt is non writeable by the user, but writeable by Administrators.

Start the installer, observe that the installer asks for administrator privileges and creates a lot of files in c:\Qt

Finally get a error message: "Could not write installer configuration to c:\Qt\qtcreator-2.7.83/QtCreatorUninst.ini"

Apparently the administrator privileges are dropped too early or not used for writing that file.